diff --git a/backend/alembic/versions/010_make_community_id_nullable.py b/backend/alembic/versions/010_make_community_id_nullable.py
new file mode 100644
index 0000000..b3e0cee
--- /dev/null
+++ b/backend/alembic/versions/010_make_community_id_nullable.py
@@ -0,0 +1,86 @@
+"""将 events / event_templates / contents / campaigns 的 community_id 改为可选（nullable）
+
+架构重构：从「社区隔离」改为「社区关联」模式
+- 活动、内容、运营活动、生态洞察可独立存在，通过 community_id 属性可选关联到社区
+- 委员会、会议仍保持强社区绑定
+
+Revision ID: 010_make_community_id_nullable
+Revises: 009_add_ecosystem_community_id
+Create Date: 2026-02-23
+"""
+import sqlalchemy as sa
+from alembic import op
+
+revision = "010_make_community_id_nullable"
+down_revision = "009_add_ecosystem_community_id"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    # events.community_id: NOT NULL → nullable
+    with op.batch_alter_table("events") as batch_op:
+        batch_op.alter_column(
+            "community_id",
+            existing_type=sa.Integer(),
+            nullable=True,
+        )
+
+    # event_templates.community_id: NOT NULL → nullable
+    with op.batch_alter_table("event_templates") as batch_op:
+        batch_op.alter_column(
+            "community_id",
+            existing_type=sa.Integer(),
+            nullable=True,
+        )
+
+    # contents.community_id: NOT NULL → nullable
+    with op.batch_alter_table("contents") as batch_op:
+        batch_op.alter_column(
+            "community_id",
+            existing_type=sa.Integer(),
+            nullable=True,
+        )
+
+    # campaigns.community_id: NOT NULL → nullable
+    with op.batch_alter_table("campaigns") as batch_op:
+        batch_op.alter_column(
+            "community_id",
+            existing_type=sa.Integer(),
+            nullable=True,
+        )
+
+    # ecosystem_projects.community_id was already added as nullable in 009,
+    # but model shows nullable=False. No DDL change needed here since SQLite
+    # already has it nullable; the model fix is done in the ORM layer.
+
+
+def downgrade() -> None:
+    # Note: downgrade may fail if there are rows with NULL community_id
+    with op.batch_alter_table("campaigns") as batch_op:
+        batch_op.alter_column(
+            "community_id",
+            existing_type=sa.Integer(),
+            nullable=False,
+        )
+
+    with op.batch_alter_table("contents") as batch_op:
+        batch_op.alter_column(
+            "community_id",
+            existing_type=sa.Integer(),
+            nullable=False,
+        )
+
+    with op.batch_alter_table("event_templates") as batch_op:
+        batch_op.alter_column(
+            "community_id",
+            existing_type=sa.Integer(),
+            nullable=False,
+        )
+
+    with op.batch_alter_table("events") as batch_op:
+        batch_op.alter_column(
+            "community_id",
+            existing_type=sa.Integer(),
+            nullable=False,
+        )
diff --git a/backend/app/api/campaigns.py b/backend/app/api/campaigns.py
index 5f35d71..e99fd10 100644
--- a/backend/app/api/campaigns.py
+++ b/backend/app/api/campaigns.py
@@ -4,7 +4,7 @@
 from sqlalchemy import func
 from sqlalchemy.orm import Session, joinedload
 
-from app.core.dependencies import get_current_community, get_current_user
+from app.core.dependencies import get_current_user
 from app.database import get_db
 from app.models import User
 from app.models.campaign import Campaign, CampaignActivity, CampaignContact
@@ -39,11 +39,10 @@
 def list_campaigns(
     type: str | None = None,
     status: str | None = None,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
-    query = db.query(Campaign).filter(Campaign.community_id == community_id)
+    query = db.query(Campaign)
     if type:
         query = query.filter(Campaign.type == type)
     if status:
@@ -54,14 +53,12 @@ def list_campaigns(
 @router.post("", response_model=CampaignOut, status_code=201)
 def create_campaign(
     data: CampaignCreate,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
     if data.type not in VALID_TYPES:
         raise HTTPException(400, f"type 必须为 {VALID_TYPES}")
     campaign = Campaign(
-        community_id=community_id,
         owner_id=current_user.id,
         **data.model_dump(),
     )
@@ -74,12 +71,11 @@ def create_campaign(
 @router.get("/{cid}", response_model=CampaignOut)
 def get_campaign(
     cid: int,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
     campaign = db.query(Campaign).filter(
-        Campaign.id == cid, Campaign.community_id == community_id
+        Campaign.id == cid
     ).first()
     if not campaign:
         raise HTTPException(404, "运营活动不存在")
@@ -90,12 +86,11 @@ def get_campaign(
 def update_campaign(
     cid: int,
     data: CampaignUpdate,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
     campaign = db.query(Campaign).filter(
-        Campaign.id == cid, Campaign.community_id == community_id
+        Campaign.id == cid
     ).first()
     if not campaign:
         raise HTTPException(404, "运营活动不存在")
@@ -114,12 +109,11 @@ def update_campaign(
 @router.get("/{cid}/funnel", response_model=CampaignFunnel)
 def campaign_funnel(
     cid: int,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
     campaign = db.query(Campaign).filter(
-        Campaign.id == cid, Campaign.community_id == community_id
+        Campaign.id == cid
     ).first()
     if not campaign:
         raise HTTPException(404, "运营活动不存在")
@@ -149,12 +143,11 @@ def list_contacts(
     status: str | None = None,
     page: int = Query(1, ge=1),
     page_size: int = Query(20, ge=1, le=100),
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
     campaign = db.query(Campaign).filter(
-        Campaign.id == cid, Campaign.community_id == community_id
+        Campaign.id == cid
     ).first()
     if not campaign:
         raise HTTPException(404, "运营活动不存在")
@@ -170,12 +163,11 @@ def list_contacts(
 def add_contact(
     cid: int,
     data: ContactCreate,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
     campaign = db.query(Campaign).filter(
-        Campaign.id == cid, Campaign.community_id == community_id
+        Campaign.id == cid
     ).first()
     if not campaign:
         raise HTTPException(404, "运营活动不存在")
@@ -202,7 +194,6 @@ def update_contact_status(
     cid: int,
     contact_id: int,
     data: ContactStatusUpdate,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
@@ -229,20 +220,18 @@ def update_contact_status(
 def import_from_event(
     cid: int,
     data: BulkImportFromEvent,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
     """从活动签到名单批量导入联系人。"""
     campaign = db.query(Campaign).filter(
-        Campaign.id == cid, Campaign.community_id == community_id
+        Campaign.id == cid
     ).first()
     if not campaign:
         raise HTTPException(404, "运营活动不存在")
-    # 校验活动存在且属于当前社区
+    # 校验活动存在
     event = db.query(Event).filter(
         Event.id == data.event_id,
-        Event.community_id == community_id,
     ).first()
     if not event:
         raise HTTPException(404, "活动不存在")
@@ -272,13 +261,12 @@ def import_from_event(
 def import_from_people(
     cid: int,
     data: BulkImportFromPeople,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
     """从人脉库批量导入指定 person_id 列表。"""
     campaign = db.query(Campaign).filter(
-        Campaign.id == cid, Campaign.community_id == community_id
+        Campaign.id == cid
     ).first()
     if not campaign:
         raise HTTPException(404, "运营活动不存在")
@@ -319,7 +307,6 @@ def import_from_people(
 def list_activities(
     cid: int,
     contact_id: int,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
@@ -345,7 +332,6 @@ def add_activity(
     cid: int,
     contact_id: int,
     data: ActivityCreate,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
diff --git a/backend/app/api/contents.py b/backend/app/api/contents.py
index 1a942f7..f0e22d7 100644
--- a/backend/app/api/contents.py
+++ b/backend/app/api/contents.py
@@ -5,7 +5,7 @@
 from sqlalchemy import select as sa_select
 from sqlalchemy.orm import Session
 
-from app.core.dependencies import check_content_edit_permission, get_current_community, get_current_user
+from app.core.dependencies import check_content_edit_permission, get_current_user
 from app.database import get_db
 from app.models import Content, User
 from app.models.content import content_communities
@@ -73,12 +73,13 @@ def list_contents(
     status: str | None = None,
     source_type: str | None = None,
     keyword: str | None = None,
-    community_id: int = Depends(get_current_community),
+    community_id: int | None = Query(None),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
-    # 通过 content_communities 关联表过滤（兼容遷移期间的 community_id 列）
-    query = db.query(Content).filter(_build_community_filter(community_id))
+    query = db.query(Content)
+    if community_id is not None:
+        query = query.filter(_build_community_filter(community_id))
 
     if status:
         query = query.filter(Content.status == status)
@@ -94,13 +95,14 @@ def list_contents(
 @router.post("", response_model=ContentOut, status_code=201)
 def create_content(
     data: ContentCreate,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
     if data.source_type not in VALID_SOURCE_TYPES:
         raise HTTPException(400, f"Invalid source_type, must be one of {VALID_SOURCE_TYPES}")
     content_html = convert_markdown_to_html(data.content_markdown) if data.content_markdown else ""
+    # 主社区：优先取 community_ids[0]，兼容旧逻辑
+    primary_community_id = data.community_ids[0] if data.community_ids else None
     content = Content(
         title=data.title,
         content_markdown=data.content_markdown,
@@ -112,7 +114,7 @@ def create_content(
         cover_image=data.cover_image,
         status="draft",
         work_status=data.work_status,
-        community_id=community_id,
+        community_id=primary_community_id,
         created_by_user_id=current_user.id,
         owner_id=current_user.id,  # Creator is the initial owner
         scheduled_publish_at=data.scheduled_publish_at,
@@ -120,9 +122,9 @@ def create_content(
     db.add(content)
     db.flush()  # Get content ID
 
-    # 写入多社区关联（未指定则关联当前社区）
-    target_community_ids = data.community_ids if data.community_ids else [community_id]
-    _write_content_communities(db, content.id, target_community_ids, current_user.id)
+    # 写入多社区关联（仅在提供了 community_ids 时）
+    if data.community_ids:
+        _write_content_communities(db, content.id, data.community_ids, current_user.id)
 
     # Assign assignees (default to creator if empty) — batch query to avoid N+1
     assignee_ids = data.assignee_ids if data.assignee_ids else [current_user.id]
@@ -143,14 +145,10 @@ def create_content(
 @router.get("/{content_id}", response_model=ContentOut)
 def get_content(
     content_id: int,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
-    content = db.query(Content).filter(
-        Content.id == content_id,
-        _build_community_filter(community_id),
-    ).first()
+    content = db.query(Content).filter(Content.id == content_id).first()
     if not content:
         raise HTTPException(404, "Content not found")
 
@@ -166,14 +164,10 @@ def get_content(
 def update_content(
     content_id: int,
     data: ContentUpdate,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
-    content = db.query(Content).filter(
-        Content.id == content_id,
-        _build_community_filter(community_id),
-    ).first()
+    content = db.query(Content).filter(Content.id == content_id).first()
     if not content:
         raise HTTPException(404, "Content not found")
 
@@ -229,14 +223,10 @@ def update_content(
 @router.delete("/{content_id}", status_code=204)
 def delete_content(
     content_id: int,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
-    content = db.query(Content).filter(
-        Content.id == content_id,
-        _build_community_filter(community_id),
-    ).first()
+    content = db.query(Content).filter(Content.id == content_id).first()
     if not content:
         raise HTTPException(404, "Content not found")
 
@@ -252,16 +242,12 @@ def delete_content(
 def update_content_status(
     content_id: int,
     data: ContentStatusUpdate,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
     if data.status not in VALID_STATUSES:
         raise HTTPException(400, f"Invalid status, must be one of {VALID_STATUSES}")
-    content = db.query(Content).filter(
-        Content.id == content_id,
-        _build_community_filter(community_id),
-    ).first()
+    content = db.query(Content).filter(Content.id == content_id).first()
     if not content:
         raise HTTPException(404, "Content not found")
 
@@ -285,17 +271,13 @@ def update_content_status(
 @router.get("/{content_id}/collaborators")
 def list_collaborators(
     content_id: int,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
     """
     List collaborators of a content.
     """
-    content = db.query(Content).filter(
-        Content.id == content_id,
-        _build_community_filter(community_id),
-    ).first()
+    content = db.query(Content).filter(Content.id == content_id).first()
     if not content:
         raise HTTPException(404, "Content not found")
 
@@ -313,7 +295,6 @@ def list_collaborators(
 def add_collaborator(
     content_id: int,
     user_id: int,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
@@ -321,10 +302,7 @@ def add_collaborator(
     Add a collaborator to a content.
     Only the owner can add collaborators.
     """
-    content = db.query(Content).filter(
-        Content.id == content_id,
-        _build_community_filter(community_id),
-    ).first()
+    content = db.query(Content).filter(Content.id == content_id).first()
     if not content:
         raise HTTPException(404, "Content not found")
 
@@ -332,14 +310,10 @@ def add_collaborator(
     if content.owner_id != current_user.id and not current_user.is_superuser:
         raise HTTPException(403, "Only the content owner can add collaborators")
 
-    # Check if user exists and is a member of the community
     user = db.query(User).filter(User.id == user_id).first()
     if not user:
         raise HTTPException(404, "User not found")
 
-    if not current_user.is_superuser and user not in content.community.members:
-        raise HTTPException(400, "User is not a member of this community")
-
     # Check if already a collaborator
     if user in content.collaborators:
         raise HTTPException(400, "User is already a collaborator")
@@ -354,7 +328,6 @@ def add_collaborator(
 def remove_collaborator(
     content_id: int,
     user_id: int,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
@@ -362,10 +335,7 @@ def remove_collaborator(
     Remove a collaborator from a content.
     Only the owner can remove collaborators.
     """
-    content = db.query(Content).filter(
-        Content.id == content_id,
-        _build_community_filter(community_id),
-    ).first()
+    content = db.query(Content).filter(Content.id == content_id).first()
     if not content:
         raise HTTPException(404, "Content not found")
 
@@ -388,7 +358,6 @@ def remove_collaborator(
 def transfer_ownership(
     content_id: int,
     new_owner_id: int,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
@@ -396,10 +365,7 @@ def transfer_ownership(
     Transfer content ownership to another user.
     Only the current owner or superuser can transfer ownership.
     """
-    content = db.query(Content).filter(
-        Content.id == content_id,
-        _build_community_filter(community_id),
-    ).first()
+    content = db.query(Content).filter(Content.id == content_id).first()
     if not content:
         raise HTTPException(404, "Content not found")
 
@@ -407,14 +373,10 @@ def transfer_ownership(
     if content.owner_id != current_user.id and not current_user.is_superuser:
         raise HTTPException(403, "Only the content owner can transfer ownership")
 
-    # Check if new owner exists and is a member of the community
     new_owner = db.query(User).filter(User.id == new_owner_id).first()
     if not new_owner:
         raise HTTPException(404, "New owner not found")
 
-    if not current_user.is_superuser and new_owner not in content.community.members:
-        raise HTTPException(400, "New owner is not a member of this community")
-
     content.owner_id = new_owner_id
     db.commit()
     db.refresh(content)
@@ -435,7 +397,7 @@ def list_calendar_events(
     start: str = Query(..., description="Start date ISO format (e.g. 2026-02-01)"),
     end: str = Query(..., description="End date ISO format (e.g. 2026-03-01)"),
     status: str | None = None,
-    community_id: int = Depends(get_current_community),
+    community_id: int | None = Query(None),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
@@ -450,7 +412,9 @@ def list_calendar_events(
     except ValueError:
         raise HTTPException(400, "Invalid date format. Use ISO format (e.g. 2026-02-01)") from None
 
-    query = db.query(Content).filter(_build_community_filter(community_id))
+    query = db.query(Content)
+    if community_id is not None:
+        query = query.filter(_build_community_filter(community_id))
 
     if status:
         query = query.filter(Content.status == status)
@@ -482,17 +446,13 @@ def list_calendar_events(
 def update_content_schedule(
     content_id: int,
     data: ContentScheduleUpdate,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
     """
     更新内容的排期发布时间（用于日历拖拽）。
     """
-    content = db.query(Content).filter(
-        Content.id == content_id,
-        _build_community_filter(community_id),
-    ).first()
+    content = db.query(Content).filter(Content.id == content_id).first()
     if not content:
         raise HTTPException(404, "Content not found")
 
diff --git a/backend/app/api/ecosystem.py b/backend/app/api/ecosystem.py
index 1cda254..55549ff 100644
--- a/backend/app/api/ecosystem.py
+++ b/backend/app/api/ecosystem.py
@@ -2,7 +2,7 @@
 from sqlalchemy.orm import Session
 
 from app.config import settings
-from app.core.dependencies import get_current_community, get_current_user
+from app.core.dependencies import get_current_user
 from app.database import get_db
 from app.models import User
 from app.models.ecosystem import EcosystemContributor, EcosystemProject
@@ -26,22 +26,19 @@
 
 @router.get("", response_model=list[ProjectListOut])
 def list_projects(
-    community_id: int = Depends(get_current_community),
+    community_id: int | None = Query(None),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
-    return (
-        db.query(EcosystemProject)
-        .filter(EcosystemProject.community_id == community_id)
-        .order_by(EcosystemProject.created_at.desc())
-        .all()
-    )
+    query = db.query(EcosystemProject)
+    if community_id is not None:
+        query = query.filter(EcosystemProject.community_id == community_id)
+    return query.order_by(EcosystemProject.created_at.desc()).all()
 
 
 @router.post("", response_model=ProjectOut, status_code=201)
 def create_project(
     data: ProjectCreate,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
@@ -49,7 +46,6 @@ def create_project(
         raise HTTPException(400, f"platform 必须为 {VALID_PLATFORMS}")
     project = EcosystemProject(
         added_by_id=current_user.id,
-        community_id=community_id,
         **data.model_dump(),
     )
     db.add(project)
@@ -61,14 +57,10 @@ def create_project(
 @router.get("/{pid}", response_model=ProjectOut)
 def get_project(
     pid: int,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
-    project = db.query(EcosystemProject).filter(
-        EcosystemProject.id == pid,
-        EcosystemProject.community_id == community_id,
-    ).first()
+    project = db.query(EcosystemProject).filter(EcosystemProject.id == pid).first()
     if not project:
         raise HTTPException(404, "项目不存在")
     return project
@@ -78,14 +70,10 @@ def get_project(
 def update_project(
     pid: int,
     data: ProjectUpdate,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
-    project = db.query(EcosystemProject).filter(
-        EcosystemProject.id == pid,
-        EcosystemProject.community_id == community_id,
-    ).first()
+    project = db.query(EcosystemProject).filter(EcosystemProject.id == pid).first()
     if not project:
         raise HTTPException(404, "项目不存在")
     for key, value in data.model_dump(exclude_unset=True).items():
@@ -100,15 +88,11 @@ def update_project(
 @router.post("/{pid}/sync", response_model=SyncResult)
 def trigger_sync(
     pid: int,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
     """手动触发单个项目同步。"""
-    project = db.query(EcosystemProject).filter(
-        EcosystemProject.id == pid,
-        EcosystemProject.community_id == community_id,
-    ).first()
+    project = db.query(EcosystemProject).filter(EcosystemProject.id == pid).first()
     if not project:
         raise HTTPException(404, "项目不存在")
     token = getattr(settings, "GITHUB_PAT", None)
@@ -125,14 +109,10 @@ def list_contributors(
     unlinked: bool = False,
     page: int = Query(1, ge=1),
     page_size: int = Query(20, ge=1, le=100),
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
-    project = db.query(EcosystemProject).filter(
-        EcosystemProject.id == pid,
-        EcosystemProject.community_id == community_id,
-    ).first()
+    project = db.query(EcosystemProject).filter(EcosystemProject.id == pid).first()
     if not project:
         raise HTTPException(404, "项目不存在")
     query = db.query(EcosystemContributor).filter(EcosystemContributor.project_id == pid)
@@ -155,16 +135,11 @@ def list_contributors(
 def import_contributor_to_people(
     pid: int,
     handle: str,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
     """将贡献者导入人脉库，并关联 person_id。"""
-    # 校验项目属于当前社区
-    project = db.query(EcosystemProject).filter(
-        EcosystemProject.id == pid,
-        EcosystemProject.community_id == community_id,
-    ).first()
+    project = db.query(EcosystemProject).filter(EcosystemProject.id == pid).first()
     if not project:
         raise HTTPException(404, "项目不存在")
 
diff --git a/backend/app/api/event_templates.py b/backend/app/api/event_templates.py
index 9772345..964c756 100644
--- a/backend/app/api/event_templates.py
+++ b/backend/app/api/event_templates.py
@@ -1,7 +1,7 @@
 from fastapi import APIRouter, Depends, HTTPException
 from sqlalchemy.orm import Session
 
-from app.core.dependencies import get_current_community, get_current_user
+from app.core.dependencies import get_current_user
 from app.database import get_db
 from app.models import User
 from app.models.event import ChecklistTemplateItem, EventTemplate
@@ -12,15 +12,12 @@
 
 @router.get("", response_model=list[EventTemplateListOut])
 def list_templates(
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
     return (
         db.query(EventTemplate)
-        .filter(
-            (EventTemplate.community_id == community_id) | (EventTemplate.is_public == True)  # noqa: E712
-        )
+        .filter(EventTemplate.is_public == True)  # noqa: E712
         .order_by(EventTemplate.created_at.desc())
         .all()
     )
@@ -29,12 +26,11 @@ def list_templates(
 @router.post("", response_model=EventTemplateOut, status_code=201)
 def create_template(
     data: EventTemplateCreate,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
     template = EventTemplate(
-        community_id=community_id,
+        community_id=None,
         name=data.name,
         event_type=data.event_type,
         description=data.description,
@@ -56,14 +52,13 @@ def create_template(
 @router.get("/{template_id}", response_model=EventTemplateOut)
 def get_template(
     template_id: int,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
     template = db.query(EventTemplate).filter(EventTemplate.id == template_id).first()
     if not template:
         raise HTTPException(404, "模板不存在")
-    if template.community_id != community_id and not template.is_public:
+    if not template.is_public:
         raise HTTPException(403, "无权访问此模板")
     return template
 
@@ -72,14 +67,10 @@ def get_template(
 def update_template(
     template_id: int,
     data: EventTemplateUpdate,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
-    template = db.query(EventTemplate).filter(
-        EventTemplate.id == template_id,
-        EventTemplate.community_id == community_id,
-    ).first()
+    template = db.query(EventTemplate).filter(EventTemplate.id == template_id).first()
     if not template:
         raise HTTPException(404, "模板不存在")
     for key, value in data.model_dump(exclude_unset=True).items():
diff --git a/backend/app/api/events.py b/backend/app/api/events.py
index ccdca53..f1dbfc9 100644
--- a/backend/app/api/events.py
+++ b/backend/app/api/events.py
@@ -1,7 +1,7 @@
 from fastapi import APIRouter, Depends, HTTPException, Query
 from sqlalchemy.orm import Session
 
-from app.core.dependencies import get_current_community, get_current_user
+from app.core.dependencies import get_current_user
 from app.database import get_db
 from app.models import User
 from app.models.event import (
@@ -48,13 +48,15 @@
 def list_events(
     status: str | None = None,
     event_type: str | None = None,
+    community_id: int | None = Query(None),
     page: int = Query(1, ge=1),
     page_size: int = Query(20, ge=1, le=100),
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
-    query = db.query(Event).filter(Event.community_id == community_id)
+    query = db.query(Event)
+    if community_id is not None:
+        query = query.filter(Event.community_id == community_id)
     if status:
         query = query.filter(Event.status == status)
     if event_type:
@@ -67,7 +69,6 @@ def list_events(
 @router.post("", response_model=EventOut, status_code=201)
 def create_event(
     data: EventCreate,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
@@ -75,7 +76,6 @@ def create_event(
         raise HTTPException(400, f"event_type 必须为 {VALID_EVENT_TYPES}")
 
     event = Event(
-        community_id=community_id,
         owner_id=current_user.id,
         **data.model_dump(),
     )
@@ -102,13 +102,10 @@ def create_event(
 @router.get("/{event_id}", response_model=EventOut)
 def get_event(
     event_id: int,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
-    event = db.query(Event).filter(
-        Event.id == event_id, Event.community_id == community_id
-    ).first()
+    event = db.query(Event).filter(Event.id == event_id).first()
     if not event:
         raise HTTPException(404, "活动不存在")
     return event
@@ -118,13 +115,10 @@ def get_event(
 def update_event(
     event_id: int,
     data: EventUpdate,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
-    event = db.query(Event).filter(
-        Event.id == event_id, Event.community_id == community_id
-    ).first()
+    event = db.query(Event).filter(Event.id == event_id).first()
     if not event:
         raise HTTPException(404, "活动不存在")
     for key, value in data.model_dump(exclude_unset=True).items():
@@ -138,15 +132,12 @@ def update_event(
 def update_event_status(
     event_id: int,
     data: EventStatusUpdate,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
     if data.status not in VALID_EVENT_STATUSES:
         raise HTTPException(400, f"status 必须为 {VALID_EVENT_STATUSES}")
-    event = db.query(Event).filter(
-        Event.id == event_id, Event.community_id == community_id
-    ).first()
+    event = db.query(Event).filter(Event.id == event_id).first()
     if not event:
         raise HTTPException(404, "活动不存在")
     event.status = data.status
@@ -160,13 +151,10 @@ def update_event_status(
 @router.get("/{event_id}/checklist", response_model=list[ChecklistItemOut])
 def get_checklist(
     event_id: int,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
-    event = db.query(Event).filter(
-        Event.id == event_id, Event.community_id == community_id
-    ).first()
+    event = db.query(Event).filter(Event.id == event_id).first()
     if not event:
         raise HTTPException(404, "活动不存在")
     return sorted(event.checklist_items, key=lambda x: (x.phase, x.order))
@@ -177,7 +165,6 @@ def update_checklist_item(
     event_id: int,
     item_id: int,
     data: ChecklistItemUpdate,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
@@ -198,13 +185,10 @@ def update_checklist_item(
 @router.get("/{event_id}/personnel", response_model=list[EventPersonnelOut])
 def list_personnel(
     event_id: int,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
-    event = db.query(Event).filter(
-        Event.id == event_id, Event.community_id == community_id
-    ).first()
+    event = db.query(Event).filter(Event.id == event_id).first()
     if not event:
         raise HTTPException(404, "活动不存在")
     return sorted(event.personnel, key=lambda x: x.order)
@@ -214,13 +198,10 @@ def list_personnel(
 def add_personnel(
     event_id: int,
     data: EventPersonnelCreate,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
-    event = db.query(Event).filter(
-        Event.id == event_id, Event.community_id == community_id
-    ).first()
+    event = db.query(Event).filter(Event.id == event_id).first()
     if not event:
         raise HTTPException(404, "活动不存在")
     person = EventPersonnel(event_id=event_id, **data.model_dump())
@@ -235,7 +216,6 @@ def confirm_personnel(
     event_id: int,
     pid: int,
     data: PersonnelConfirmUpdate,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
@@ -256,14 +236,11 @@ def confirm_personnel(
 def import_attendees(
     event_id: int,
     rows: list[dict],
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
     """批量导入签到名单。每行需包含 person_id 字段（已确认匹配的 PersonProfile ID）。"""
-    event = db.query(Event).filter(
-        Event.id == event_id, Event.community_id == community_id
-    ).first()
+    event = db.query(Event).filter(Event.id == event_id).first()
     if not event:
         raise HTTPException(404, "活动不存在")
 
@@ -299,13 +276,10 @@ def import_attendees(
 @router.get("/{event_id}/feedback", response_model=list[FeedbackOut])
 def list_feedback(
     event_id: int,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
-    event = db.query(Event).filter(
-        Event.id == event_id, Event.community_id == community_id
-    ).first()
+    event = db.query(Event).filter(Event.id == event_id).first()
     if not event:
         raise HTTPException(404, "活动不存在")
     return event.feedback_items
@@ -315,13 +289,10 @@ def list_feedback(
 def create_feedback(
     event_id: int,
     data: FeedbackCreate,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
-    event = db.query(Event).filter(
-        Event.id == event_id, Event.community_id == community_id
-    ).first()
+    event = db.query(Event).filter(Event.id == event_id).first()
     if not event:
         raise HTTPException(404, "活动不存在")
     feedback = FeedbackItem(event_id=event_id, **data.model_dump())
@@ -336,7 +307,6 @@ def update_feedback(
     event_id: int,
     fid: int,
     data: FeedbackStatusUpdate,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
@@ -357,7 +327,6 @@ def link_issue(
     event_id: int,
     fid: int,
     data: IssueLinkCreate,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
@@ -396,13 +365,10 @@ def _build_task_tree(tasks: list[EventTask]) -> list[EventTask]:
 @router.get("/{event_id}/tasks", response_model=list[EventTaskOut])
 def list_tasks(
     event_id: int,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
-    event = db.query(Event).filter(
-        Event.id == event_id, Event.community_id == community_id
-    ).first()
+    event = db.query(Event).filter(Event.id == event_id).first()
     if not event:
         raise HTTPException(404, "活动不存在")
     tasks = db.query(EventTask).filter(EventTask.event_id == event_id).order_by(EventTask.order).all()
@@ -413,13 +379,10 @@ def list_tasks(
 def create_task(
     event_id: int,
     data: EventTaskCreate,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
-    event = db.query(Event).filter(
-        Event.id == event_id, Event.community_id == community_id
-    ).first()
+    event = db.query(Event).filter(Event.id == event_id).first()
     if not event:
         raise HTTPException(404, "活动不存在")
     task = EventTask(event_id=event_id, **data.model_dump())
@@ -435,7 +398,6 @@ def update_task(
     event_id: int,
     tid: int,
     data: EventTaskUpdate,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
@@ -456,7 +418,6 @@ def update_task(
 def delete_task(
     event_id: int,
     tid: int,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
@@ -473,13 +434,10 @@ def delete_task(
 def reorder_tasks(
     event_id: int,
     data: TaskReorderRequest,
-    community_id: int = Depends(get_current_community),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db),
 ):
-    event = db.query(Event).filter(
-        Event.id == event_id, Event.community_id == community_id
-    ).first()
+    event = db.query(Event).filter(Event.id == event_id).first()
     if not event:
         raise HTTPException(404, "活动不存在")
     for item in data.tasks:
diff --git a/backend/app/models/campaign.py b/backend/app/models/campaign.py
index d1e132f..19f7154 100644
--- a/backend/app/models/campaign.py
+++ b/backend/app/models/campaign.py
@@ -10,7 +10,7 @@ class Campaign(Base):
     __tablename__ = "campaigns"
 
     id = Column(Integer, primary_key=True, index=True)
-    community_id = Column(Integer, ForeignKey("communities.id", ondelete="CASCADE"), nullable=False, index=True)
+    community_id = Column(Integer, ForeignKey("communities.id", ondelete="CASCADE"), nullable=True, index=True)
     name = Column(String(300), nullable=False)
     description = Column(Text, nullable=True)
     type = Column(String(50), nullable=False)          # promotion / care / invitation / survey
diff --git a/backend/app/models/content.py b/backend/app/models/content.py
index b9eb5d9..30b7bda 100644
--- a/backend/app/models/content.py
+++ b/backend/app/models/content.py
@@ -64,7 +64,7 @@ class Content(Base):
     # Work status (工作状态): planning, in_progress, completed
     work_status = Column(String(50), default="planning", index=True)
     # Multi-tenancy fields
-    community_id = Column(Integer, ForeignKey("communities.id", ondelete="CASCADE"), nullable=False, index=True)
+    community_id = Column(Integer, ForeignKey("communities.id", ondelete="CASCADE"), nullable=True, index=True)
     created_by_user_id = Column(Integer, ForeignKey("users.id", ondelete="SET NULL"), nullable=True, index=True)
     # Ownership field (defaults to creator)
     owner_id = Column(Integer, ForeignKey("users.id", ondelete="SET NULL"), nullable=True, index=True)
diff --git a/backend/app/models/ecosystem.py b/backend/app/models/ecosystem.py
index eca5265..252d042 100644
--- a/backend/app/models/ecosystem.py
+++ b/backend/app/models/ecosystem.py
@@ -10,7 +10,7 @@ class EcosystemProject(Base):
     __tablename__ = "ecosystem_projects"
 
     id = Column(Integer, primary_key=True, index=True)
-    community_id = Column(Integer, ForeignKey("communities.id", ondelete="CASCADE"), nullable=False, index=True)
+    community_id = Column(Integer, ForeignKey("communities.id", ondelete="CASCADE"), nullable=True, index=True)
     name = Column(String(200), nullable=False)
     platform = Column(String(30), nullable=False)   # github / gitee / gitcode
     org_name = Column(String(200), nullable=False)
diff --git a/backend/app/models/event.py b/backend/app/models/event.py
index 3538a41..eab7489 100644
--- a/backend/app/models/event.py
+++ b/backend/app/models/event.py
@@ -13,7 +13,7 @@ class EventTemplate(Base):
 
     id = Column(Integer, primary_key=True)
     community_id = Column(
-        Integer, ForeignKey("communities.id", ondelete="CASCADE"), nullable=False, index=True
+        Integer, ForeignKey("communities.id", ondelete="CASCADE"), nullable=True, index=True
     )
     name = Column(String(200), nullable=False)
     event_type = Column(
@@ -55,7 +55,7 @@ class Event(Base):
 
     id = Column(Integer, primary_key=True)
     community_id = Column(
-        Integer, ForeignKey("communities.id", ondelete="CASCADE"), nullable=False, index=True
+        Integer, ForeignKey("communities.id", ondelete="CASCADE"), nullable=True, index=True
     )
     title = Column(String(300), nullable=False)
     event_type = Column(
diff --git a/backend/app/schemas/campaign.py b/backend/app/schemas/campaign.py
index c0150af..44f62bb 100644
--- a/backend/app/schemas/campaign.py
+++ b/backend/app/schemas/campaign.py
@@ -7,6 +7,7 @@
 class CampaignCreate(BaseModel):
     name: str
     type: str  # promotion / care / invitation / survey
+    community_id: int | None = None
     description: str | None = None
     target_count: int | None = None
     start_date: date | None = None
@@ -25,7 +26,7 @@ class CampaignUpdate(BaseModel):
 
 class CampaignListOut(BaseModel):
     id: int
-    community_id: int
+    community_id: int | None
     name: str
     type: str
     status: str
diff --git a/backend/app/schemas/content.py b/backend/app/schemas/content.py
index 51812d1..51477ac 100644
--- a/backend/app/schemas/content.py
+++ b/backend/app/schemas/content.py
@@ -52,7 +52,7 @@ class ContentOut(BaseModel):
     cover_image: str | None
     status: str
     work_status: str
-    community_id: int
+    community_id: int | None
     created_by_user_id: int | None
     owner_id: int | None
     scheduled_publish_at: datetime | None
diff --git a/backend/app/schemas/ecosystem.py b/backend/app/schemas/ecosystem.py
index 4ca626f..a855fd7 100644
--- a/backend/app/schemas/ecosystem.py
+++ b/backend/app/schemas/ecosystem.py
@@ -9,6 +9,7 @@ class ProjectCreate(BaseModel):
     platform: str           # github / gitee / gitcode
     org_name: str
     repo_name: str | None = None
+    community_id: int | None = None
     description: str | None = None
     tags: list[str] = []
 
diff --git a/backend/app/schemas/event.py b/backend/app/schemas/event.py
index 7a8e3a8..ff70e40 100644
--- a/backend/app/schemas/event.py
+++ b/backend/app/schemas/event.py
@@ -38,7 +38,7 @@ class EventTemplateUpdate(BaseModel):
 
 class EventTemplateOut(BaseModel):
     id: int
-    community_id: int
+    community_id: int | None
     name: str
     event_type: str
     description: str | None
@@ -65,6 +65,7 @@ class EventTemplateListOut(BaseModel):
 class EventCreate(BaseModel):
     title: str
     event_type: str = "offline"
+    community_id: int | None = None
     template_id: int | None = None
     planned_at: datetime | None = None
     duration_minutes: int | None = None
@@ -98,7 +99,7 @@ class EventStatusUpdate(BaseModel):
 
 class EventOut(BaseModel):
     id: int
-    community_id: int
+    community_id: int | None
     title: str
     event_type: str
     template_id: int | None
diff --git a/backend/tests/test_calendar_api.py b/backend/tests/test_calendar_api.py
index b68146d..1c7b191 100644
--- a/backend/tests/test_calendar_api.py
+++ b/backend/tests/test_calendar_api.py
@@ -173,7 +173,7 @@ def test_get_calendar_events_requires_auth(
         )
         assert response.status_code in [401, 403]
 
-    def test_get_calendar_events_community_isolation(
+    def test_get_calendar_events_cross_community(
         self,
         client: TestClient,
         db_session: Session,
@@ -181,7 +181,7 @@ def test_get_calendar_events_community_isolation(
         test_another_community: Community,
         auth_headers: dict,
     ):
-        """社区隔离：只能看到自己社区的数据"""
+        """跨社区：内容日历展示所有社区的内容（community association 模式）"""
         now = datetime.utcnow()
         db_session.add(
             Content(
@@ -203,8 +203,10 @@ def test_get_calendar_events_community_isolation(
             f"/api/contents/calendar/events?start={start}&end={end}",
             headers=auth_headers,
         )
+        assert response.status_code == 200
         data = response.json()
-        assert not any(item["title"] == "Other Community Event" for item in data)
+        # 跨社区内容对所有用户可见
+        assert any(item["title"] == "Other Community Event" for item in data)
 
     def test_get_calendar_events_response_fields(
         self,
diff --git a/backend/tests/test_campaigns_api.py b/backend/tests/test_campaigns_api.py
index 9f1128f..148c998 100644
--- a/backend/tests/test_campaigns_api.py
+++ b/backend/tests/test_campaigns_api.py
@@ -124,9 +124,10 @@ def test_get_campaign_not_found(self, client: TestClient, auth_headers):
         resp = client.get("/api/campaigns/99999", headers=auth_headers)
         assert resp.status_code == 404
 
-    def test_get_campaign_wrong_community(self, client: TestClient, another_user_auth_headers, test_campaign):
+    def test_get_campaign_cross_community_accessible(self, client: TestClient, another_user_auth_headers, test_campaign):
+        """运营活动采用 community association 模式，跨社区用户也可访问"""
         resp = client.get(f"/api/campaigns/{test_campaign.id}", headers=another_user_auth_headers)
-        assert resp.status_code == 404
+        assert resp.status_code == 200
 
 
 class TestUpdateCampaign:
diff --git a/backend/tests/test_contents_api.py b/backend/tests/test_contents_api.py
index 371215a..5519a37 100644
--- a/backend/tests/test_contents_api.py
+++ b/backend/tests/test_contents_api.py
@@ -178,7 +178,7 @@ def test_list_contents_keyword_search(
         assert data["total"] == 1
         assert "Python" in data["items"][0]["title"]
 
-    def test_list_contents_community_isolation(
+    def test_list_contents_cross_community(
         self,
         client: TestClient,
         db_session: Session,
@@ -186,7 +186,7 @@ def test_list_contents_community_isolation(
         test_another_community: Community,
         auth_headers: dict,
     ):
-        """Test contents are isolated by community."""
+        """内容采用 community association 模式，所有社区内容均可见（跨社区列表）"""
         # Create content in test_community
         content1 = Content(
             title="My Content",
@@ -208,12 +208,14 @@ def test_list_contents_community_isolation(
         db_session.add_all([content1, content2])
         db_session.commit()
 
-        # Should only see content from test_community
+        # 跨社区：两个社区的内容均可见
         response = client.get("/api/contents", headers=auth_headers)
         assert response.status_code == 200
         data = response.json()
-        assert data["total"] == 1
-        assert data["items"][0]["title"] == "My Content"
+        assert data["total"] == 2
+        titles = {item["title"] for item in data["items"]}
+        assert "My Content" in titles
+        assert "Other Content" in titles
 
     def test_list_contents_no_auth(self, client: TestClient):
         """Test listing contents fails without authentication."""
@@ -341,7 +343,7 @@ def test_get_content_from_another_community(
         test_another_community: Community,
         auth_headers: dict,
     ):
-        """Test cannot access content from another community."""
+        """内容采用 community association 模式，可跨社区访问其他社区的内容"""
         content = Content(
             title="Other Content",
             content_markdown="Test",
@@ -354,7 +356,7 @@ def test_get_content_from_another_community(
         db_session.commit()
 
         response = client.get(f"/api/contents/{content.id}", headers=auth_headers)
-        assert response.status_code == 404  # Should not find it
+        assert response.status_code == 200  # 跨社区内容可访问
 
 
 class TestUpdateContent:
diff --git a/backend/tests/test_ecosystem_api.py b/backend/tests/test_ecosystem_api.py
index e33bea8..3964313 100644
--- a/backend/tests/test_ecosystem_api.py
+++ b/backend/tests/test_ecosystem_api.py
@@ -60,10 +60,11 @@ def test_list_projects_returns_data(self, client: TestClient, auth_headers, test
         assert len(data) == 1
         assert data[0]["name"] == "openGecko"
 
-    def test_list_projects_community_isolation(self, client: TestClient, another_user_auth_headers, test_project):
+    def test_list_projects_cross_community(self, client: TestClient, another_user_auth_headers, test_project):
+        """生态项目采用 community association 模式，跨社区用户也可看到项目列表"""
         resp = client.get("/api/ecosystem", headers=another_user_auth_headers)
         assert resp.status_code == 200
-        assert resp.json() == []
+        assert len(resp.json()) >= 1
 
 
 class TestCreateProject:
@@ -108,9 +109,10 @@ def test_get_project_not_found(self, client: TestClient, auth_headers):
         resp = client.get("/api/ecosystem/99999", headers=auth_headers)
         assert resp.status_code == 404
 
-    def test_get_project_wrong_community(self, client: TestClient, another_user_auth_headers, test_project):
+    def test_get_project_cross_community_accessible(self, client: TestClient, another_user_auth_headers, test_project):
+        """生态项目采用 community association 模式，跨社区用户可访问项目详情"""
         resp = client.get(f"/api/ecosystem/{test_project.id}", headers=another_user_auth_headers)
-        assert resp.status_code == 404
+        assert resp.status_code == 200
 
 
 class TestUpdateProject:
diff --git a/backend/tests/test_event_templates_api.py b/backend/tests/test_event_templates_api.py
index a884eb3..b48cfca 100644
--- a/backend/tests/test_event_templates_api.py
+++ b/backend/tests/test_event_templates_api.py
@@ -33,17 +33,21 @@ def test_list_empty(self, client: TestClient, auth_headers: dict):
         assert resp.status_code == 200
         assert resp.json() == []
 
-    def test_list_returns_community_templates(
+    def test_list_returns_public_templates_only(
         self,
         client: TestClient,
         auth_headers: dict,
         db_session: Session,
         test_community: Community,
     ):
-        _create_template(db_session, test_community.id, name="私有模板")
+        """列表仅返回公开模板，私有模板不出现"""
+        _create_template(db_session, test_community.id, name="私有模板", is_public=False)
+        _create_template(db_session, test_community.id, name="公开模板", is_public=True)
         resp = client.get("/api/event-templates", headers=auth_headers)
         assert resp.status_code == 200
-        assert any(t["name"] == "私有模板" for t in resp.json())
+        names = [t["name"] for t in resp.json()]
+        assert "公开模板" in names
+        assert "私有模板" not in names
 
     def test_list_includes_public_templates(
         self,
@@ -110,7 +114,8 @@ def test_get_existing_template(
         db_session: Session,
         test_community: Community,
     ):
-        t = _create_template(db_session, test_community.id)
+        """GET 公开模板返回 200"""
+        t = _create_template(db_session, test_community.id, is_public=True)
         resp = client.get(f"/api/event-templates/{t.id}", headers=auth_headers)
         assert resp.status_code == 200
         assert resp.json()["id"] == t.id
diff --git a/backend/tests/test_rbac_collaboration.py b/backend/tests/test_rbac_collaboration.py
index ee70a05..d94d70c 100644
--- a/backend/tests/test_rbac_collaboration.py
+++ b/backend/tests/test_rbac_collaboration.py
@@ -122,7 +122,7 @@ def test_superuser_can_access_all_communities(
         response = client.get("/api/contents", headers=headers)
         assert response.status_code == 200
     
-    def test_regular_user_cannot_access_other_communities(
+    def test_regular_user_can_access_all_contents_cross_community(
         self,
         client: TestClient,
         regular_user: User,
@@ -130,14 +130,13 @@ def test_regular_user_cannot_access_other_communities(
         test_another_community: Community,
         regular_user_token: str
     ):
-        """Regular user should only access their own communities."""
-        # Try to access another community
+        """内容采用 community association 模式，普通用户也可跨社区查看内容列表"""
         headers = {
             "Authorization": f"Bearer {regular_user_token}",
             "X-Community-Id": str(test_another_community.id),
         }
         response = client.get("/api/contents", headers=headers)
-        assert response.status_code == 403
+        assert response.status_code == 200
     
     def test_community_admin_can_edit_all_community_content(
         self,
diff --git a/frontend/src/App.vue b/frontend/src/App.vue
index a982c66..b3eee98 100644
--- a/frontend/src/App.vue
+++ b/frontend/src/App.vue
@@ -40,6 +40,10 @@
             <el-icon><Stamp /></el-icon>
             <span>社区治理</span>
           </template>
+          <el-menu-item index="/community-overview">
+            <el-icon><OfficeBuilding /></el-icon>
+            <span>社区总览</span>
+          </el-menu-item>
           <el-menu-item index="/governance">
             <el-icon><DataLine /></el-icon>
             <span>治理概览</span>
@@ -117,10 +121,6 @@
               <span>社区设置</span>
             </el-menu-item>
             <template v-if="isSuperuser">
-              <el-menu-item index="/community-overview">
-                <el-icon><OfficeBuilding /></el-icon>
-                <span>社区总览</span>
-              </el-menu-item>
               <el-menu-item index="/communities">
                 <el-icon><Setting /></el-icon>
                 <span>社区管理</span>
@@ -215,17 +215,19 @@ const showLayout = computed(() => {
 })
 
 // 判断是否显示社区选择下拉框
-// 社区总览、社区管理、用户管理、我的工作、人脉管理等平台级页面不显示
+// 仅在需要社区上下文的页面（社区工作台、社区治理）显示
 const showCommunitySwitcher = computed(() => {
-  const hideSwitcherRoutes = [
-    'CommunityOverview',
-    'CommunityManage',
-    'UserManage',
-    'WorkloadOverview',
-    'MyWork',
-    'People',
+  const showSwitcherRoutes = [
+    'CommunitySandbox',
+    'GovernanceOverview',
+    'CommitteeList',
+    'CommitteeDetail',
+    'CommitteeMemberManage',
+    'MeetingCalendar',
+    'MeetingDetail',
+    'CommunitySettings',
   ]
-  return !hideSwitcherRoutes.includes(route.name as string)
+  return showSwitcherRoutes.includes(route.name as string)
 })
 
 onMounted(async () => {
diff --git a/frontend/src/api/campaign.ts b/frontend/src/api/campaign.ts
index 2c07b67..c7136e7 100644
--- a/frontend/src/api/campaign.ts
+++ b/frontend/src/api/campaign.ts
@@ -4,7 +4,7 @@ import apiClient from './index'
 
 export interface CampaignListItem {
   id: number
-  community_id: number
+  community_id: number | null
   name: string
   type: string
   status: string
@@ -23,6 +23,7 @@ export interface CampaignDetail extends CampaignListItem {
 export interface CampaignCreate {
   name: string
   type: string
+  community_id?: number | null
   description?: string | null
   target_count?: number | null
   start_date?: string | null
diff --git a/frontend/src/api/ecosystem.ts b/frontend/src/api/ecosystem.ts
index 6a90c88..af7510d 100644
--- a/frontend/src/api/ecosystem.ts
+++ b/frontend/src/api/ecosystem.ts
@@ -47,6 +47,7 @@ export interface ProjectCreateData {
   platform: string
   org_name: string
   repo_name?: string
+  community_id?: number | null
   description?: string
   tags?: string[]
 }
diff --git a/frontend/src/api/event.ts b/frontend/src/api/event.ts
index e5018f1..2e22169 100644
--- a/frontend/src/api/event.ts
+++ b/frontend/src/api/event.ts
@@ -15,7 +15,7 @@ export interface EventListItem {
 
 export interface EventDetail {
   id: number
-  community_id: number
+  community_id: number | null
   title: string
   event_type: string
   template_id: number | null
@@ -40,6 +40,7 @@ export interface EventDetail {
 export interface EventCreate {
   title: string
   event_type?: string
+  community_id?: number | null
   template_id?: number | null
   planned_at?: string | null
   duration_minutes?: number | null
diff --git a/frontend/src/views/Campaigns.vue b/frontend/src/views/Campaigns.vue
index 320c673..671b4af 100644
--- a/frontend/src/views/Campaigns.vue
+++ b/frontend/src/views/Campaigns.vue
@@ -6,7 +6,7 @@
         <h1 class="page-title">运营活动</h1>
         <p class="page-subtitle">Campaign 策划、联系人漏斗与跟进管理</p>
       </div>
-      <el-button type="primary" :disabled="!hasCommunity" @click="openCreateDialog">
+      <el-button type="primary" @click="openCreateDialog">
         <el-icon><Plus /></el-icon>
         创建运营活动
       </el-button>
@@ -32,8 +32,7 @@
     <div v-loading="loading" class="campaign-grid">
       <div v-if="!loading && campaigns.length === 0" class="empty-state">
         <el-icon class="empty-icon"><MagicStick /></el-icon>
-        <p v-if="!hasCommunity">请先在顶部选择社区</p>
-        <p v-else>暂无运营活动，点击右上角创建</p>
+        <p>暂无运营活动，点击右上角创建</p>
       </div>
 
       <div
@@ -77,6 +76,11 @@
         <el-form-item label="结束日期">
           <el-date-picker v-model="createForm.end_date" type="date" value-format="YYYY-MM-DD" style="width: 100%" />
         </el-form-item>
+        <el-form-item label="关联社区">
+          <el-select v-model="createForm.community_id" placeholder="可选，关联到某社区" clearable style="width: 100%">
+            <el-option v-for="c in communities" :key="c.id" :label="c.name" :value="c.id" />
+          </el-select>
+        </el-form-item>
         <el-form-item label="描述">
           <el-input v-model="createForm.description" type="textarea" :rows="2" />
         </el-form-item>
@@ -96,11 +100,11 @@ import { ElMessage } from 'element-plus'
 import { MagicStick, Plus, User, Calendar } from '@element-plus/icons-vue'
 import { listCampaigns, createCampaign } from '../api/campaign'
 import type { CampaignListItem } from '../api/campaign'
-import { useCommunityStore } from '../stores/community'
+import { useAuthStore } from '../stores/auth'
 
 const router = useRouter()
-const communityStore = useCommunityStore()
-const hasCommunity = computed(() => !!communityStore.currentCommunityId)
+const authStore = useAuthStore()
+const communities = computed(() => authStore.communities)
 const loading = ref(false)
 const creating = ref(false)
 const campaigns = ref<CampaignListItem[]>([])
@@ -111,6 +115,7 @@ const showCreateDialog = ref(false)
 const createForm = ref({
   name: '',
   type: 'promotion',
+  community_id: null as number | null,
   target_count: null as number | null,
   start_date: null as string | null,
   end_date: null as string | null,
@@ -123,10 +128,6 @@ const statusLabel: Record<string, string> = { draft: '草稿', active: '进行
 const statusTagMap: Record<string, '' | 'primary' | 'success' | 'warning' | 'danger' | 'info'> = { draft: 'info', active: 'primary', completed: 'success', archived: '' }
 
 async function loadCampaigns() {
-  if (!hasCommunity.value) {
-    campaigns.value = []
-    return
-  }
   loading.value = true
   try {
     campaigns.value = await listCampaigns({
@@ -141,7 +142,7 @@ async function loadCampaigns() {
 }
 
 function openCreateDialog() {
-  createForm.value = { name: '', type: 'promotion', target_count: null, start_date: null, end_date: null, description: '' }
+  createForm.value = { name: '', type: 'promotion', community_id: null, target_count: null, start_date: null, end_date: null, description: '' }
   showCreateDialog.value = true
 }
 
@@ -152,6 +153,7 @@ async function handleCreate() {
     const c = await createCampaign({
       name: createForm.value.name,
       type: createForm.value.type,
+      community_id: createForm.value.community_id || null,
       target_count: createForm.value.target_count || null,
       start_date: createForm.value.start_date || null,
       end_date: createForm.value.end_date || null,
diff --git a/frontend/src/views/EcosystemList.vue b/frontend/src/views/EcosystemList.vue
index 4982cfd..ed1eeac 100644
--- a/frontend/src/views/EcosystemList.vue
+++ b/frontend/src/views/EcosystemList.vue
@@ -6,7 +6,7 @@
         <h1 class="page-title">生态洞察</h1>
         <p class="page-subtitle">监控开源生态项目，追踪贡献者动态</p>
       </div>
-      <el-button type="primary" :disabled="!hasCommunity" @click="openCreateDialog">
+      <el-button type="primary" @click="openCreateDialog">
         <el-icon><Plus /></el-icon>
         添加项目
       </el-button>
@@ -16,8 +16,7 @@
     <div v-loading="loading" class="project-grid">
       <div v-if="!loading && projects.length === 0" class="empty-state">
         <el-icon class="empty-icon"><Connection /></el-icon>
-        <p v-if="!hasCommunity">请先在顶部选择社区</p>
-        <p v-else>暂无生态项目，点击右上角添加</p>
+        <p>暂无生态项目，点击右上角添加</p>
       </div>
 
       <div
@@ -64,6 +63,11 @@
         <el-form-item label="仓库名">
           <el-input v-model="createForm.repo_name" placeholder="如: kruise（留空=整个组织）" />
         </el-form-item>
+        <el-form-item label="关联社区">
+          <el-select v-model="createForm.community_id" placeholder="可选，关联到某社区" clearable style="width: 100%">
+            <el-option v-for="c in communities" :key="c.id" :label="c.name" :value="c.id" />
+          </el-select>
+        </el-form-item>
         <el-form-item label="描述">
           <el-input v-model="createForm.description" type="textarea" :rows="2" />
         </el-form-item>
@@ -81,10 +85,10 @@ import { onMounted, ref, computed } from 'vue'
 import { ElMessage } from 'element-plus'
 import { Plus, Connection, Refresh } from '@element-plus/icons-vue'
 import { listProjects, createProject, type EcosystemProject, type ProjectCreateData } from '../api/ecosystem'
-import { useCommunityStore } from '../stores/community'
+import { useAuthStore } from '../stores/auth'
 
-const communityStore = useCommunityStore()
-const hasCommunity = computed(() => !!communityStore.currentCommunityId)
+const authStore = useAuthStore()
+const communities = computed(() => authStore.communities)
 const loading = ref(false)
 const projects = ref<EcosystemProject[]>([])
 const showCreateDialog = ref(false)
@@ -96,6 +100,7 @@ const createForm = ref({
   org_name: '',
   repo_name: '',
   description: '',
+  community_id: null as number | null,
 })
 
 function formatDate(iso: string) {
@@ -103,10 +108,6 @@ function formatDate(iso: string) {
 }
 
 async function loadProjects() {
-  if (!hasCommunity.value) {
-    projects.value = []
-    return
-  }
   loading.value = true
   try {
     projects.value = await listProjects()
@@ -118,7 +119,7 @@ async function loadProjects() {
 }
 
 function openCreateDialog() {
-  createForm.value = { name: '', platform: 'github', org_name: '', repo_name: '', description: '' }
+  createForm.value = { name: '', platform: 'github', org_name: '', repo_name: '', description: '', community_id: null }
   showCreateDialog.value = true
 }
 
@@ -133,6 +134,7 @@ async function handleCreate() {
       name: createForm.value.name,
       platform: createForm.value.platform,
       org_name: createForm.value.org_name,
+      community_id: createForm.value.community_id || null,
     }
     if (createForm.value.repo_name) payload.repo_name = createForm.value.repo_name
     if (createForm.value.description) payload.description = createForm.value.description
diff --git a/frontend/src/views/Events.vue b/frontend/src/views/Events.vue
index 31846ff..9c27df8 100644
--- a/frontend/src/views/Events.vue
+++ b/frontend/src/views/Events.vue
@@ -6,7 +6,7 @@
         <h1 class="page-title">活动管理</h1>
         <p class="page-subtitle">策划、执行和复盘社区活动全流程</p>
       </div>
-      <el-button type="primary" :disabled="!hasCommunity" @click="openCreateDialog">
+      <el-button type="primary" @click="openCreateDialog">
         <el-icon><Plus /></el-icon>
         创建活动
       </el-button>
@@ -32,8 +32,7 @@
     <div v-loading="loading" class="events-grid">
       <div v-if="!loading && events.length === 0" class="empty-state">
         <el-icon class="empty-icon"><Flag /></el-icon>
-        <p v-if="!hasCommunity">请先在顶部选择社区</p>
-        <p v-else>暂无活动，点击右上角创建第一个活动</p>
+        <p>暂无活动，点击右上角创建第一个活动</p>
       </div>
       <div
         v-for="event in events"
@@ -93,6 +92,16 @@
         <el-form-item label="地点">
           <el-input v-model="createForm.location" placeholder="活动地点（线下填写）" />
         </el-form-item>
+        <el-form-item label="关联社区">
+          <el-select v-model="createForm.community_id" placeholder="可选，关联到某社区" clearable style="width: 100%">
+            <el-option
+              v-for="c in communities"
+              :key="c.id"
+              :label="c.name"
+              :value="c.id"
+            />
+          </el-select>
+        </el-form-item>
         <el-form-item label="简介">
           <el-input v-model="createForm.description" type="textarea" :rows="3" placeholder="活动简介" />
         </el-form-item>
@@ -112,11 +121,11 @@ import { ElMessage } from 'element-plus'
 import { Flag, Plus, Calendar, Location } from '@element-plus/icons-vue'
 import { listEvents, createEvent } from '../api/event'
 import type { EventListItem } from '../api/event'
-import { useCommunityStore } from '../stores/community'
+import { useAuthStore } from '../stores/auth'
 
 const router = useRouter()
-const communityStore = useCommunityStore()
-const hasCommunity = computed(() => !!communityStore.currentCommunityId)
+const authStore = useAuthStore()
+const communities = computed(() => authStore.communities)
 
 const loading = ref(false)
 const creating = ref(false)
@@ -131,6 +140,7 @@ const showCreateDialog = ref(false)
 const createForm = ref({
   title: '',
   event_type: 'offline',
+  community_id: null as number | null,
   planned_at: null as string | null,
   location: '',
   description: '',
@@ -170,11 +180,6 @@ function formatDate(dt: string | null): string {
 }
 
 async function loadEvents() {
-  if (!hasCommunity.value) {
-    events.value = []
-    total.value = 0
-    return
-  }
   loading.value = true
   try {
     const data = await listEvents({
@@ -193,7 +198,7 @@ async function loadEvents() {
 }
 
 function openCreateDialog() {
-  createForm.value = { title: '', event_type: 'offline', planned_at: null, location: '', description: '' }
+  createForm.value = { title: '', event_type: 'offline', community_id: null, planned_at: null, location: '', description: '' }
   showCreateDialog.value = true
 }
 
@@ -207,6 +212,7 @@ async function handleCreate() {
     const event = await createEvent({
       title: createForm.value.title,
       event_type: createForm.value.event_type,
+      community_id: createForm.value.community_id || null,
       planned_at: createForm.value.planned_at || null,
       location: createForm.value.location || null,
       description: createForm.value.description || null,