diff --git a/.changeset/chilled-pillows-joke.md b/.changeset/chilled-pillows-joke.md
new file mode 100644
index 00000000..7c379b41
--- /dev/null
+++ b/.changeset/chilled-pillows-joke.md
@@ -0,0 +1,5 @@
+---
+'@ice/pkg': minor
+---
+
+feat: umd format will enable inlineDynamicImports
diff --git a/packages/pkg/src/engine/shared/outputs.ts b/packages/pkg/src/engine/shared/outputs.ts
index 7ebcf99b..f77c7632 100644
--- a/packages/pkg/src/engine/shared/outputs.ts
+++ b/packages/pkg/src/engine/shared/outputs.ts
@@ -77,11 +77,16 @@ export function getOutputs({
       if (minify) {
         options.plugins = [minifyPlugin(bundleTaskConfig.sourcemap, typeof minify === 'boolean' ? {} : minify.options)];
       }
+      options.inlineDynamicImports = format.module === 'umd';
     } else if (engine === 'rolldown') {
       const rolldownOuptut = options as RolldownOutputOptions;
       if (minify) {
         rolldownOuptut.minify = typeof minify === 'boolean' ? minify : minify.options;
       }
+      // rolldown can auto handle umd format to disable codeSplitting
+      // if (format.module === 'umd') {
+      //   rolldownOuptut.codeSplitting = false
+      // }
     }
 
     return options;
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index def8f98d..49c3bc6f 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -611,6 +611,9 @@ importers:
       '@ice/pkg':
         specifier: workspace:*
         version: link:../../../packages/pkg
+      '@swc/helpers':
+        specifier: ^0.5.15
+        version: 0.5.17
       es-toolkit:
         specifier: ^1.32.0
         version: 1.32.0
diff --git a/tests/integration/bundle-dep/__snapshots__/index.test.ts.snap b/tests/integration/bundle-dep/__snapshots__/index.test.ts.snap
index c8ca6f6a..e94c0080 100644
--- a/tests/integration/bundle-dep/__snapshots__/index.test.ts.snap
+++ b/tests/integration/bundle-dep/__snapshots__/index.test.ts.snap
@@ -56,3 +56,71 @@ exports[`Run config default-venders > dist structure 1`] = `
   "name": "dist",
 }
 `;
+
+exports[`Run config dynamic-import > dist structure 1`] = `
+{
+  "files": [
+    {
+      "name": "dynamic-import.umd.es5.production.js",
+    },
+  ],
+  "name": "dist",
+}
+`;
+
+exports[`Run config dynamic-import-pkg > dist structure 1`] = `
+{
+  "files": [
+    {
+      "name": "dynamic-import.cjs.es5.production.js",
+    },
+    {
+      "name": "dynamic-import.esm.es5.production.js",
+    },
+    {
+      "name": "dynamic-import.umd.es5.production.js",
+    },
+    {
+      "name": "vendor.cjs.es5.production.js",
+    },
+    {
+      "name": "vendor.esm.es5.production.js",
+    },
+  ],
+  "name": "dist",
+}
+`;
+
+exports[`Run config dynamic-import-pkg-rolldown > dist structure 1`] = `
+{
+  "files": [
+    {
+      "name": "dynamic-import.cjs.es5.production.js",
+    },
+    {
+      "name": "dynamic-import.esm.es5.production.js",
+    },
+    {
+      "name": "dynamic-import.umd.es5.production.js",
+    },
+    {
+      "name": "vendor.cjs.es5.production.js",
+    },
+    {
+      "name": "vendor.esm.es5.production.js",
+    },
+  ],
+  "name": "dist",
+}
+`;
+
+exports[`Run config dynamic-import-rolldown > dist structure 1`] = `
+{
+  "files": [
+    {
+      "name": "dynamic-import.umd.es5.production.js",
+    },
+  ],
+  "name": "dist",
+}
+`;
diff --git a/tests/integration/bundle-dep/index.test.ts b/tests/integration/bundle-dep/index.test.ts
index faf70897..010275e8 100644
--- a/tests/integration/bundle-dep/index.test.ts
+++ b/tests/integration/bundle-dep/index.test.ts
@@ -46,6 +46,43 @@ const tests: ProjectTestUserConfig[] = [
       ],
     },
   },
+  // should inlineDynamicImport for umd
+  {
+    name: 'dynamic-import',
+    config: {
+      entry: './src/dynamic-import.ts',
+      bundle: {
+        // rollup has error when using umd and cjs in same instance
+        // https://github.com/rollup/rollup/issues/6296
+        formats: ['umd'],
+      },
+    },
+    engine: ['rollup', 'rolldown'],
+  },
+  {
+    name: 'dynamic-import-pkg',
+    config: {
+      entry: './src/dynamic-import.ts',
+      pkgs: [
+        {
+          module: 'esm',
+          target: 'es5',
+          bundle: true,
+        },
+        {
+          module: 'cjs',
+          target: 'es5',
+          bundle: true,
+        },
+        {
+          module: 'umd',
+          target: 'es5',
+          bundle: true,
+        },
+      ],
+    },
+    engine: ['rollup', 'rolldown'],
+  },
 ];
 
 runProjectTest(
diff --git a/tests/integration/bundle-dep/package.json b/tests/integration/bundle-dep/package.json
index 3ba0a6d7..3d9d45e7 100644
--- a/tests/integration/bundle-dep/package.json
+++ b/tests/integration/bundle-dep/package.json
@@ -4,6 +4,7 @@
   "private": true,
   "dependencies": {
     "@ice/pkg": "workspace:*",
+    "@swc/helpers": "^0.5.15",
     "es-toolkit": "^1.32.0"
   }
 }
diff --git a/tests/integration/bundle-dep/src/dynamic-import.ts b/tests/integration/bundle-dep/src/dynamic-import.ts
new file mode 100644
index 00000000..849a88ba
--- /dev/null
+++ b/tests/integration/bundle-dep/src/dynamic-import.ts
@@ -0,0 +1,4 @@
+export async function load() {
+  const { merge } = await import('es-toolkit');
+  return merge;
+}