diff --git a/CHANGELOG.md b/CHANGELOG.md
index 27835e1..9986bb1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,6 @@
 # [4.9.8+x]
 * SmartDialog.config.checkExist() adjust to SmartDialog.checkExist()
+* Fix [#209](https://github.com/fluttercandies/flutter_smart_dialog/issues/209)
 
 * # [4.9.7+x]
 * optimize bindWidget, when bindWidget is not null, bindPage will be automatically set to false.
diff --git a/example/lib/demo/issue209.dart b/example/lib/demo/issue209.dart
new file mode 100644
index 0000000..9af16b8
--- /dev/null
+++ b/example/lib/demo/issue209.dart
@@ -0,0 +1,56 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_smart_dialog/flutter_smart_dialog.dart';
+
+void main() => runApp(const MyApp());
+
+class MyApp extends StatelessWidget {
+  const MyApp({Key? key}) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      home: Scaffold(
+        body: Center(
+          child: ElevatedButton(
+            onPressed: () => _show(),
+            child: const Text('show'),
+          ),
+        ),
+      ),
+      navigatorObservers: [FlutterSmartDialog.observer],
+      builder: FlutterSmartDialog.init(),
+    );
+  }
+
+  void _show() async {
+    print("before:${DateTime.now().millisecondsSinceEpoch}");
+    var result = await SmartDialog.show<bool>(
+        tag: 'tag',
+        backDismiss: false,
+        clickMaskDismiss: false,
+        builder: (_) {
+          return ElevatedButton(
+            onPressed: () {
+              SmartDialog.dismiss(tag: 'tag', result: true);
+            },
+            child: const Text('关闭Dialog，显示Loading'),
+          );
+        },
+        onDismiss: () {
+          print("onDismiss:${DateTime.now().millisecondsSinceEpoch}");
+          // showLoading()放在这里能正常显示
+          // SmartDialog.showLoading();
+        });
+
+    print("aftermiss:${DateTime.now().millisecondsSinceEpoch}");
+    if (result == true) {
+      // showLoading() 放在这里需要加一点延时才能显示Loading
+      // await Future.delayed(const Duration(seconds: 1));
+      SmartDialog.showLoading();
+
+      // 延时关闭Loading
+      await Future.delayed(const Duration(seconds: 2));
+      SmartDialog.dismiss();
+    }
+  }
+}
diff --git a/lib/src/custom/main_dialog.dart b/lib/src/custom/main_dialog.dart
index 0479445..c486ed6 100644
--- a/lib/src/custom/main_dialog.dart
+++ b/lib/src/custom/main_dialog.dart
@@ -226,16 +226,16 @@ class MainDialog {
       Navigator.pop(DialogProxy.contextNavigator!);
     }
 
+    await DialogProxy.instance.smartOverlayController.dismiss();
+
+    // safety await
+    await ViewUtils.awaitPostFrame();
+
     //end waiting
     _handleAwaitOver<T>(
       awaitOverType: SmartAwaitOverType.dialogDismiss,
       result: result,
     );
-
-    await DialogProxy.instance.smartOverlayController.dismiss();
-
-    // safety await
-    await Future.delayed(const Duration(milliseconds: 20));
   }
 
   Widget getWidget() => Offstage(offstage: !visible, child: _widget);
diff --git a/lib/src/kit/view_utils.dart b/lib/src/kit/view_utils.dart
index 7818ec3..d2a108a 100644
--- a/lib/src/kit/view_utils.dart
+++ b/lib/src/kit/view_utils.dart
@@ -1,4 +1,5 @@
-import 'package:flutter/cupertino.dart';
+import 'dart:async';
+
 import 'package:flutter/material.dart';
 import 'package:flutter/scheduler.dart';
 
@@ -14,6 +15,31 @@ class ViewUtils {
     }
   }
 
+  static Future<void> awaitSafeUse({VoidCallback? onPostFrame}) async {
+    final completer = Completer();
+    var schedulerPhase = schedulerBinding.schedulerPhase;
+    if (schedulerPhase == SchedulerPhase.persistentCallbacks) {
+      widgetsBinding.addPostFrameCallback((timeStamp) {
+        onPostFrame?.call();
+        if (!completer.isCompleted) completer.complete();
+      });
+    } else {
+      onPostFrame?.call();
+      if (!completer.isCompleted) completer.complete();
+    }
+
+    await completer.future;
+  }
+
+  static Future<void> awaitPostFrame({VoidCallback? onPostFrame}) async {
+    final completer = Completer();
+    widgetsBinding.addPostFrameCallback((timeStamp) {
+      onPostFrame?.call();
+      if (!completer.isCompleted) completer.complete();
+    });
+    await completer.future;
+  }
+
   static bool isDarkModel() {
     if (DialogProxy.contextNavigator == null) {
       return false;
diff --git a/lib/src/widget/helper/smart_overlay.dart b/lib/src/widget/helper/smart_overlay.dart
index 15a8eff..f9e1fc4 100644
--- a/lib/src/widget/helper/smart_overlay.dart
+++ b/lib/src/widget/helper/smart_overlay.dart
@@ -46,12 +46,9 @@ class _SmartOverlayState extends State<SmartOverlay> {
     if (showCompleter?.isCompleted == false) showCompleter?.complete();
     showCompleter = Completer();
 
-    var completer = Completer();
-    ViewUtils.addSafeUse(() {
+    await ViewUtils.awaitSafeUse(onPostFrame: () {
       setState(() => visible = true);
-      completer.complete();
     });
-    await completer.future;
 
     // await show isExist
     widgetsBinding.addPostFrameCallback((timeStamp) {
diff --git a/pubspec.yaml b/pubspec.yaml
index 37ef2bc..845434a 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -3,7 +3,7 @@ description:
   An elegant Flutter Dialog solution,
   Easily implement Toast, Loading and custom Dialog,
   Make the use of the dialog easier!
-version: 4.9.8
+version: 4.9.8+1
 homepage: https://github.com/fluttercandies/flutter_smart_dialog
 # flutter pub publish --server=https://pub.dartlang.org
 # flutter build web --release --base-href="/flutter_smart_dialog/web/"