diff --git a/src/renderer/components/Sidebar/Sidebar.tsx b/src/renderer/components/Sidebar/Sidebar.tsx
index f376fc6..fae158c 100644
--- a/src/renderer/components/Sidebar/Sidebar.tsx
+++ b/src/renderer/components/Sidebar/Sidebar.tsx
@@ -17,10 +17,29 @@ export function Sidebar() {
   const setRootPath = useSidebarStore(s => s.setRootPath)
   const setTree = useSidebarStore(s => s.setTree)
   const isVisible = useSidebarStore(s => s.isVisible)
+  const expandDirs = useSidebarStore(s => s.expandDirs)
 
   // 计算当前活动标签的文件路径（用于文件树高亮）
   const activeFilePath = tabs.find(t => t.id === activeTabId)?.filePath ?? null
 
+  // 自动展开到活动文件所在的目录
+  useEffect(() => {
+    if (!activeFilePath || !rootPath) return
+    if (!activeFilePath.startsWith(rootPath)) return
+
+    // 提取文件的所有父目录路径
+    const dirsToExpand: string[] = []
+    let dir = activeFilePath.replace(/[/\\][^/\\]+$/, '') // 移除文件名
+    while (dir && dir.length >= rootPath.length && dir !== rootPath) {
+      dirsToExpand.push(dir)
+      dir = dir.replace(/[/\\][^/\\]+$/, '')
+    }
+
+    if (dirsToExpand.length > 0) {
+      expandDirs(dirsToExpand)
+    }
+  }, [activeFilePath, rootPath, expandDirs])
+
   const [isResizing, setIsResizing] = useState(false)
   const sidebarRef = useRef<HTMLDivElement>(null)
 
diff --git a/src/renderer/stores/sidebarStore.ts b/src/renderer/stores/sidebarStore.ts
index 59f8355..01ae671 100644
--- a/src/renderer/stores/sidebarStore.ts
+++ b/src/renderer/stores/sidebarStore.ts
@@ -12,6 +12,7 @@ interface SidebarState {
   setRootPath: (path: string | null) => void
   setTree: (tree: FileNode[]) => void
   toggleDir: (path: string) => void
+  expandDirs: (paths: string[]) => void
   setSidebarWidth: (width: number) => void
 }
 
@@ -35,5 +36,17 @@ export const useSidebarStore = create<SidebarState>((set) => ({
       }
       return { expandedDirs: newSet }
     }),
+  expandDirs: (paths) =>
+    set(state => {
+      const newSet = new Set(state.expandedDirs)
+      let changed = false
+      for (const p of paths) {
+        if (!newSet.has(p)) {
+          newSet.add(p)
+          changed = true
+        }
+      }
+      return changed ? { expandedDirs: newSet } : state
+    }),
   setSidebarWidth: (width) => set({ sidebarWidth: width })
 }))