diff --git a/client/lib/main.dart b/client/lib/main.dart
index 4522380..39b83b5 100644
--- a/client/lib/main.dart
+++ b/client/lib/main.dart
@@ -1,5 +1,6 @@
 // main.dart — 入口(演示态)
 // 串接:登录 → 引导 → 主框架(4 Tab);状态层统一走 Riverpod。
+import 'dart:io';
 import 'dart:ui' as ui;
 
 import 'package:flutter/material.dart';
@@ -18,8 +19,11 @@ import 'widgets/pangolin_logo.dart';
 
 Future<void> main() async {
   WidgetsFlutterBinding.ensureInitialized();
-  // 桌面端:常驻系统托盘,关闭窗口隐藏到托盘而非退出。
+  // 桌面端:单实例 + 常驻系统托盘(关闭窗口隐藏到托盘而非退出)。
   if (isDesktop) {
+    if (!await ensureSingleInstance()) {
+      exit(0); // 已有实例在跑(已唤起其窗口),本进程退出。
+    }
     await TrayService.instance.init();
   }
   runApp(const ProviderScope(child: PangolinApp()));
diff --git a/client/lib/system_tray.dart b/client/lib/system_tray.dart
index 01c72fa..67edadb 100644
--- a/client/lib/system_tray.dart
+++ b/client/lib/system_tray.dart
@@ -11,6 +11,33 @@ import 'package:window_manager/window_manager.dart';
 bool get isDesktop =>
     !kIsWeb && (Platform.isMacOS || Platform.isWindows || Platform.isLinux);
 
+// 单实例锁端口(仅 loopback)。第二个实例绑定失败 → 通知首实例显示窗口后退出。
+const _singleInstancePort = 47654;
+
+/// 保证一台机器只有一个 Pangolin 进程。返回 false 表示已有实例在跑
+/// (本进程应退出,首实例已被唤起显示)。
+Future<bool> ensureSingleInstance() async {
+  if (!isDesktop) return true;
+  try {
+    final server = await ServerSocket.bind(InternetAddress.loopbackIPv4, _singleInstancePort);
+    // 首实例:监听后续实例的"唤起"请求 → 显示并聚焦窗口。
+    server.listen((socket) {
+      socket.destroy();
+      windowManager.show();
+      windowManager.focus();
+    });
+    return true;
+  } on SocketException {
+    // 端口被占 = 已有实例 → 连过去让它显示,然后本进程退出。
+    try {
+      final s = await Socket.connect(InternetAddress.loopbackIPv4, _singleInstancePort,
+          timeout: const Duration(seconds: 1));
+      s.destroy();
+    } catch (_) {}
+    return false;
+  }
+}
+
 class TrayService with TrayListener, WindowListener {
   TrayService._();
   static final TrayService instance = TrayService._();
diff --git a/client/macos/Runner/AppDelegate.swift b/client/macos/Runner/AppDelegate.swift
index b3c1761..da810b5 100644
--- a/client/macos/Runner/AppDelegate.swift
+++ b/client/macos/Runner/AppDelegate.swift
@@ -3,8 +3,10 @@ import FlutterMacOS
 
 @main
 class AppDelegate: FlutterAppDelegate {
+  // 托盘常驻:关闭窗口只隐藏到托盘,不终止 app(window_manager preventClose + hide
+  // 负责隐藏;此处 false 兜底,确保即便窗口真关闭 app 也留在托盘)。
   override func applicationShouldTerminateAfterLastWindowClosed(_ sender: NSApplication) -> Bool {
-    return true
+    return false
   }
 
   override func applicationSupportsSecureRestorableState(_ app: NSApplication) -> Bool {