diff --git a/lib/core/config/app_config.dart b/lib/core/config/app_config.dart
index a75bc96..98baefc 100644
--- a/lib/core/config/app_config.dart
+++ b/lib/core/config/app_config.dart
@@ -11,11 +11,10 @@ import 'package:flutter/foundation.dart';
 class AppConfig {
   const AppConfig._();
 
-  /// 真机默认使用的开发机局域网地址。
+  /// 开发调试默认服务地址，当前直接指向公网。
   ///
-  /// 这个地址跟着电脑所在的网络走，换网络后要用
-  /// `ipconfig getifaddr en0` 重新确认。默认值只改这一行。
-  static const String devHostBaseUrl = 'http://192.168.31.187:8081';
+  /// 需要切换局域网联调时只改这一行，地址不要带结尾斜杠。
+  static const String devHostBaseUrl = 'http://39.162.50.99:8081';
 
   /// 本机后端地址：通过 `adb reverse tcp:8081 tcp:8081` 映射到开发机，
   /// 探测可达时 App 直连本机服务；不可达时回落到公网地址。
@@ -38,7 +37,7 @@ class AppConfig {
   static const List<String> _probeCandidates = [
     lanBaseUrl,
     devHostBaseUrl,
-    publicBaseUrl,
+    if (devHostBaseUrl != publicBaseUrl) publicBaseUrl,
   ];
 
   /// Build-time server URL supplied through `--dart-define=API_BASE_URL`.
diff --git a/test/config/server_endpoint_test.dart b/test/config/server_endpoint_test.dart
index 2348717..524eede 100644
--- a/test/config/server_endpoint_test.dart
+++ b/test/config/server_endpoint_test.dart
@@ -62,8 +62,8 @@ void main() {
     );
   });
 
-  test('should_use_the_configured_lan_address_for_device_default', () {
-    expect(AppConfig.devHostBaseUrl, 'http://192.168.31.187:8081');
+  test('should_use_the_configured_public_address_for_device_default', () {
+    expect(AppConfig.devHostBaseUrl, 'http://39.162.50.99:8081');
   });
 
   test('should_skip_probe_when_compiled_override_is_set', () async {
@@ -111,11 +111,7 @@ void main() {
       },
     );
 
-    expect(attempts, [
-      AppConfig.lanBaseUrl,
-      AppConfig.devHostBaseUrl,
-      AppConfig.publicBaseUrl,
-    ]);
+    expect(attempts, [AppConfig.lanBaseUrl, AppConfig.devHostBaseUrl]);
     expect(AppConfig.apiBaseUrl, AppConfig.publicBaseUrl);
   });
 
@@ -133,7 +129,7 @@ void main() {
           attempts.add(baseUrl);
           active++;
           if (active > maxActive) maxActive = active;
-          if (active == 3) allStarted.complete();
+          if (active == 2) allStarted.complete();
           await allStarted.future;
           active--;
           return baseUrl == AppConfig.lanBaseUrl ||
@@ -143,17 +139,13 @@ void main() {
 
       await probing.timeout(const Duration(seconds: 1));
 
-      expect(attempts, [
-        AppConfig.lanBaseUrl,
-        AppConfig.devHostBaseUrl,
-        AppConfig.publicBaseUrl,
-      ]);
-      expect(maxActive, 3);
+      expect(attempts, [AppConfig.lanBaseUrl, AppConfig.devHostBaseUrl]);
+      expect(maxActive, 2);
       expect(AppConfig.apiBaseUrl, AppConfig.lanBaseUrl);
     },
   );
 
-  test('should_probe_loopback_dev_host_then_public_in_order', () async {
+  test('should_probe_loopback_then_public_in_order', () async {
     final attempts = <String>[];
 
     await AppConfig.probeAndApplyBaseUrl(
@@ -164,11 +156,7 @@ void main() {
       },
     );
 
-    expect(attempts, [
-      AppConfig.lanBaseUrl,
-      AppConfig.devHostBaseUrl,
-      AppConfig.publicBaseUrl,
-    ]);
+    expect(attempts, [AppConfig.lanBaseUrl, AppConfig.devHostBaseUrl]);
     expect(AppConfig.apiBaseUrl, AppConfig.publicBaseUrl);
   });
 
@@ -183,11 +171,7 @@ void main() {
       },
     );
 
-    expect(attempts, [
-      AppConfig.lanBaseUrl,
-      AppConfig.devHostBaseUrl,
-      AppConfig.publicBaseUrl,
-    ]);
+    expect(attempts, [AppConfig.lanBaseUrl, AppConfig.devHostBaseUrl]);
     expect(AppConfig.apiBaseUrl, AppConfig.devHostBaseUrl);
   });
 
@@ -203,12 +187,7 @@ void main() {
       },
     );
 
-    expect(attempts, [
-      custom,
-      AppConfig.lanBaseUrl,
-      AppConfig.devHostBaseUrl,
-      AppConfig.publicBaseUrl,
-    ]);
+    expect(attempts, [custom, AppConfig.lanBaseUrl, AppConfig.devHostBaseUrl]);
     expect(AppConfig.apiBaseUrl, custom);
   });