diff --git a/electron/main/index.ts b/electron/main/index.ts
index ea98581..bd4d379 100644
--- a/electron/main/index.ts
+++ b/electron/main/index.ts
@@ -116,9 +116,6 @@ class MainProcess {
       },
     })
 
-    // 设置默认日间模式
-    nativeTheme.themeSource = 'light'
-
     this.mainWindow.once('ready-to-show', () => {
       this.mainWindow?.show()
     })
diff --git a/electron/main/ipc/window.ts b/electron/main/ipc/window.ts
index 99a3f20..cd4a7c5 100644
--- a/electron/main/ipc/window.ts
+++ b/electron/main/ipc/window.ts
@@ -53,6 +53,12 @@ export function registerWindowHandlers(ctx: IpcContext): void {
     win.webContents.openDevTools()
   })
 
+  // 设置主题模式
+  ipcMain.on('window:setThemeSource', (_, mode: 'system' | 'light' | 'dark') => {
+    const { nativeTheme } = require('electron')
+    nativeTheme.themeSource = mode
+  })
+
   // ==================== 应用信息 ====================
   ipcMain.handle('app:getVersion', () => {
     return app.getVersion()
diff --git a/electron/preload/index.d.ts b/electron/preload/index.d.ts
index 85ca39f..1ddacc8 100644
--- a/electron/preload/index.d.ts
+++ b/electron/preload/index.d.ts
@@ -110,6 +110,7 @@ interface Api {
   send: (channel: string, data?: unknown) => void
   receive: (channel: string, func: (...args: unknown[]) => void) => void
   removeListener: (channel: string, func: (...args: unknown[]) => void) => void
+  setThemeSource: (mode: 'system' | 'light' | 'dark') => void
   dialog: {
     showOpenDialog: (options: Electron.OpenDialogOptions) => Promise<Electron.OpenDialogReturnValue>
   }
diff --git a/electron/preload/index.ts b/electron/preload/index.ts
index 099136c..24adf20 100644
--- a/electron/preload/index.ts
+++ b/electron/preload/index.ts
@@ -56,6 +56,9 @@ const api = {
   removeListener: (channel: string, func: (...args: unknown[]) => void) => {
     ipcRenderer.removeListener(channel, func)
   },
+  setThemeSource: (mode: 'system' | 'light' | 'dark') => {
+    ipcRenderer.send('window:setThemeSource', mode)
+  },
 }
 
 // Chat Analysis API
diff --git a/src/components/common/settings/BasicSettingsTab.vue b/src/components/common/settings/BasicSettingsTab.vue
index 84bbaeb..9e7a205 100644
--- a/src/components/common/settings/BasicSettingsTab.vue
+++ b/src/components/common/settings/BasicSettingsTab.vue
@@ -42,6 +42,17 @@ const currentLocale = computed({
   get: () => locale.value,
   set: (val: LocaleType) => settingsStore.setLocale(val),
 })
+
+// Sync theme with main process
+import { watch } from 'vue'
+watch(
+  colorMode,
+  (val) => {
+    const mode = val === 'auto' ? 'system' : (val as 'light' | 'dark')
+    window.api.setThemeSource(mode)
+  },
+  { immediate: true }
+)
 </script>
 
 <template>