diff --git a/Note/ViewController.swift b/Note/ViewController.swift
index 58a7151..d6469f2 100644
--- a/Note/ViewController.swift
+++ b/Note/ViewController.swift
@@ -35,6 +35,7 @@ class ViewController: UIViewController {
         super.viewDidLoad()
         menuItems = [loadMenuOrder()]
         setupUI()
+        setupAppStateObserver()
     }
 
     override func viewWillAppear(_ animated: Bool) {
@@ -42,6 +43,23 @@ class ViewController: UIViewController {
         updateInboxBadge()
     }
 
+    deinit {
+        NotificationCenter.default.removeObserver(self)
+    }
+
+    private func setupAppStateObserver() {
+        NotificationCenter.default.addObserver(
+            self,
+            selector: #selector(appDidBecomeActive),
+            name: UIApplication.didBecomeActiveNotification,
+            object: nil
+        )
+    }
+
+    @objc private func appDidBecomeActive() {
+        updateInboxBadge()
+    }
+
     private func setupUI() {
         title = "首页"
         navigationController?.navigationBar.prefersLargeTitles = true