diff --git a/v2rayN/v2rayN/Handler/LazyConfig.cs b/v2rayN/v2rayN/Handler/LazyConfig.cs
index 30588f97..52b0a1af 100644
--- a/v2rayN/v2rayN/Handler/LazyConfig.cs
+++ b/v2rayN/v2rayN/Handler/LazyConfig.cs
@@ -98,6 +98,11 @@ namespace v2rayN.Handler
             }
         }
 
+        public List<ProfileItem> ProfileItemsAutoSwitch()
+        {
+                return SqliteHelper.Instance.Table<ProfileItem>().Where(t => t.autoSwitch == true).ToList();
+        }
+
         public List<string> ProfileItemIndexs(string subid)
         {
             if (Utils.IsNullOrEmpty(subid))
diff --git a/v2rayN/v2rayN/Handler/MainFormHandler.cs b/v2rayN/v2rayN/Handler/MainFormHandler.cs
index 960c6ab9..4eebb1dc 100644
--- a/v2rayN/v2rayN/Handler/MainFormHandler.cs
+++ b/v2rayN/v2rayN/Handler/MainFormHandler.cs
@@ -204,7 +204,8 @@ namespace v2rayN.Handler
                 var dtNow = DateTime.Now;
                 if (config.guiItem.autoUpdateInterval > 0)
                 {
-                    if ((dtNow - autoUpdateGeoTime).Hours % config.guiItem.autoUpdateInterval == 0)
+                    var h = (dtNow - autoUpdateGeoTime).Hours;
+                    if (h>0 && h % config.guiItem.autoUpdateInterval == 0)
                     {
                         updateHandle.UpdateGeoFileAll(config, (bool success, string msg) =>
                         {
diff --git a/v2rayN/v2rayN/Handler/ServerAutoSwitch.cs b/v2rayN/v2rayN/Handler/ServerAutoSwitch.cs
new file mode 100644
index 00000000..61394a34
--- /dev/null
+++ b/v2rayN/v2rayN/Handler/ServerAutoSwitch.cs
@@ -0,0 +1,144 @@
+using DynamicData;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Interop;
+using v2rayN.Mode;
+
+namespace v2rayN.Handler
+{
+    public delegate void SetDefaultServerDelegate(string s);
+    public class TestResultItem
+    {
+        public string indexId { get; set; }
+        public long latency { get; set; }
+    }
+    internal class ServerAutoSwitch
+    {
+        private List<TestResultItem> testResultItems= new List<TestResultItem>();
+        private static readonly object objLock = new();
+        private bool bStop = false;
+        private NoticeHandler? _noticeHandler;
+        private Task taskmain = null;
+        private SetDefaultServerDelegate setDefaultServerDelegates;
+        public ServerAutoSwitch()
+        {
+           
+        }
+        ~ServerAutoSwitch()
+        {
+            Stop();
+        }
+        public void Stop()
+        {
+            bStop = true;
+            if(taskmain!=null)
+                taskmain.Wait();
+            taskmain = null;
+        }
+        public void SetDelegate(SetDefaultServerDelegate s = null) {
+            this.setDefaultServerDelegates = s;
+        }
+        private void UpdateHandler(bool notify, string msg)
+        {
+        }
+        private void UpdateSpeedtestHandler(string id, string dl, string speed)
+        {
+            lock (objLock)
+            {
+                int i;
+                bool isNumeric = Int32.TryParse(dl, out i);
+                if (!isNumeric)
+                    return;
+
+                //if (i <= 0 || id == LazyConfig.Instance.GetConfig().indexId)
+                //    return;
+
+                testResultItems.Add(new TestResultItem
+                {
+                    indexId = id,
+                    latency = i
+                });
+            }
+        }
+      
+        public void Start()
+        {
+            if (taskmain != null)
+                return;
+
+            taskmain = Task.Run(() =>
+            {
+                int iFailTimeMax = 30;
+                int iTestInterval = iFailTimeMax / 3;
+                DownloadHandle downloadHandle = new();
+                long failtimestart = 0;
+                List<ProfileItem> listprofile = new List<ProfileItem>();
+                while (!bStop)
+                {
+                    Thread.Sleep(iTestInterval * 1000);
+                    int res = downloadHandle.RunAvailabilityCheck(null).Result;
+                    if (res <= 0)
+                    {
+                        _noticeHandler?.SendMessage("Current server test failed!", true);
+                        if (failtimestart == 0)
+                            failtimestart = GetTimestamp(DateTime.Now);
+                        if (GetTimestamp(DateTime.Now) - failtimestart >= iFailTimeMax)
+                        {
+                            if (testResultItems.Count == 0 || listprofile.Count == 0)
+                                listprofile = LazyConfig.Instance.ProfileItemsAutoSwitch();
+                            if (listprofile.Count > 0)
+                            {
+                                var _config = LazyConfig.Instance.GetConfig();
+                                if (testResultItems.Count == 0)
+                                {
+                                    var _coreHandler = new CoreHandler(_config, (bool x, string y) => { });
+                                    new SpeedtestHandler(_config, _coreHandler, listprofile, Mode.ESpeedActionType.Tcping, UpdateSpeedtestHandler);
+                                    while (testResultItems.Count < listprofile.Count)
+                                    {
+                                        Thread.Sleep(20);
+                                    }
+                                }
+
+                                for(int i=testResultItems.Count-1; i>=0; i--) {
+                                    if (testResultItems[i].latency <= 0 || testResultItems[i].indexId == _config.indexId)
+                                        testResultItems.RemoveAt(i);
+                                }
+
+                                if (testResultItems.Count > 0)
+                                {
+                                    testResultItems.Sort((x, y) => x.latency.CompareTo(y.latency));
+                                    setDefaultServerDelegates(testResultItems[0].indexId);
+                                    //if (ConfigHandler.SetDefaultServerIndex(ref _config, testResultItems[0].indexId) == 0)
+                                    //{
+                                    //    RefreshServers();
+                                    //    Reload();
+                                    //}
+       
+                                    testResultItems.RemoveAt(0);
+
+                                }
+                            }
+                        }
+                    }
+                    else
+                    {
+                        failtimestart = 0;
+                        testResultItems.Clear();
+                        listprofile.Clear();
+                    }
+
+                }
+            });
+        }
+        public static long GetTimestamp(DateTime dt)
+        {
+            System.DateTime startTime = TimeZone.CurrentTimeZone.ToLocalTime(new System.DateTime(1970, 1, 1)); // 当地时区
+            long timeStamp = (long)(dt- startTime).TotalSeconds;
+            return timeStamp;
+        }
+    }
+}
diff --git a/v2rayN/v2rayN/ViewModels/MainWindowViewModel.cs b/v2rayN/v2rayN/ViewModels/MainWindowViewModel.cs
index ee306b54..989aaa6d 100644
--- a/v2rayN/v2rayN/ViewModels/MainWindowViewModel.cs
+++ b/v2rayN/v2rayN/ViewModels/MainWindowViewModel.cs
@@ -248,6 +248,10 @@ namespace v2rayN.ViewModels
 
         #endregion UI
 
+        
+
+        ServerAutoSwitch ServerAutoSwitchs= new ServerAutoSwitch();
+
         #region Init
 
         public MainWindowViewModel(ISnackbarMessageQueue snackbarMessageQueue, Action<EViewAction> updateView)
@@ -588,6 +592,8 @@ namespace v2rayN.ViewModels
 
             Reload();
             ChangeSystemProxyStatus(_config.sysProxyType, true);
+            ServerAutoSwitchs.SetDelegate(SetDefaultServer);
+            ServerAutoSwitchs.Start();
         }
 
         private void OnProgramStarted(object state, bool timeout)