diff --git a/Netch/Controllers/MainController.cs b/Netch/Controllers/MainController.cs
index ed00a620..b5fe036f 100644
--- a/Netch/Controllers/MainController.cs
+++ b/Netch/Controllers/MainController.cs
@@ -1,11 +1,11 @@
 using System;
+using System.Diagnostics;
 using System.IO;
 using System.Threading;
 using System.Threading.Tasks;
 using Netch.Models;
 using Netch.Servers.Socks5;
 using Netch.Utils;
-using static Netch.Utils.PortHelper;
 
 namespace Netch.Controllers
 {
@@ -105,10 +105,7 @@ namespace Netch.Controllers
         {
             controller = ServerHelper.GetUtilByTypeName(server.Type).GetController();
 
-            if (controller is Guard instanceController)
-                Utils.Utils.KillProcessByName(instanceController.MainFile);
-
-            PortCheck(controller.Socks5LocalPort(), "Socks5");
+            TryReleaseTcpPort(controller.Socks5LocalPort(), "Socks5");
 
             Global.MainForm.StatusText(i18N.TranslateFormat("Starting {0}", controller.Name));
 
@@ -133,13 +130,13 @@ namespace Netch.Controllers
 
         private static void StartMode(Mode mode)
         {
-            ModeController = ModeHelper.GetModeControllerByType(mode.Type, out var port, out var portName, out var portType);
+            ModeController = ModeHelper.GetModeControllerByType(mode.Type, out var port, out var portName);
 
             if (ModeController == null)
                 return;
 
             if (port != null)
-                PortCheck((ushort) port, portName, portType);
+                TryReleaseTcpPort((ushort) port, portName);
 
             Global.MainForm.StatusText(i18N.TranslateFormat("Starting {0}", ModeController.Name));
 
@@ -189,7 +186,7 @@ namespace Netch.Controllers
         {
             try
             {
-                CheckPort(port, portType);
+                PortHelper.CheckPort(port, portType);
             }
             catch (PortInUseException)
             {
@@ -200,6 +197,27 @@ namespace Netch.Controllers
                 throw new MessageException(i18N.TranslateFormat("The {0} port is reserved by system.", $"{portName} ({port})"));
             }
         }
+
+        public static void TryReleaseTcpPort(ushort port, string portName)
+        {
+            Process? p;
+            if ((p = PortHelper.GetProcessByUsedTcpPort(port)) != null)
+            {
+                if (p.MainModule!.FileName.StartsWith(Global.NetchDir))
+                {
+                    p.Kill();
+                    p.WaitForExit();
+                }
+                else
+                {
+                    throw new MessageException(i18N.TranslateFormat("The {0} port is used by {1}.",
+                        $"{portName} ({port})",
+                        $"({p.Id}){p.MainModule.FileName}"));
+                }
+            }
+
+            PortCheck(port, portName, PortType.TCP);
+        }
     }
 
     public class MessageException : Exception
diff --git a/Netch/Utils/ModeHelper.cs b/Netch/Utils/ModeHelper.cs
index 1df0d234..8d7357ff 100644
--- a/Netch/Utils/ModeHelper.cs
+++ b/Netch/Utils/ModeHelper.cs
@@ -137,17 +137,15 @@ namespace Netch.Utils
                    };
         }
 
-        public static IModeController? GetModeControllerByType(int type, out ushort? port, out string portName, out PortType portType)
+        public static IModeController? GetModeControllerByType(int type, out ushort? port, out string portName)
         {
             port = null;
             portName = string.Empty;
-            portType = PortType.Both;
             switch (type)
             {
                 case 0:
                     port = Global.Settings.RedirectorTCPPort;
                     portName = "Redirector TCP";
-                    portType = PortType.TCP;
                     return new NFController();
                 case 1:
                 case 2:
@@ -156,7 +154,6 @@ namespace Netch.Utils
                 case 5:
                     port = Global.Settings.HTTPLocalPort;
                     portName = "HTTP";
-                    portType = PortType.TCP;
                     StatusPortInfoText.HttpPort = (ushort) port;
                     return new HTTPController();
                 case 4:
diff --git a/Netch/Utils/PortHelper.cs b/Netch/Utils/PortHelper.cs
index 790ad8fe..f857cf1c 100644
--- a/Netch/Utils/PortHelper.cs
+++ b/Netch/Utils/PortHelper.cs
@@ -4,6 +4,8 @@ using System.Diagnostics;
 using System.Linq;
 using System.Net.NetworkInformation;
 using Netch.Models;
+using static Vanara.PInvoke.IpHlpApi;
+using static Vanara.PInvoke.Ws2_32;
 
 namespace Netch.Utils
 {
@@ -26,6 +28,18 @@ namespace Netch.Utils
             }
         }
 
+        public static Process? GetProcessByUsedTcpPort(ushort port)
+        {
+            if (port == 0)
+                throw new ArgumentOutOfRangeException();
+
+            var row = GetTcpTable2().SingleOrDefault(r => ntohs((ushort) r.dwLocalPort) == port);
+            if (row.dwOwningPid == 0)
+                return null;
+
+            return Process.GetProcessById((int) row.dwOwningPid);
+        }
+
         private static void GetReservedPortRange(PortType portType, ref List<Range> targetList)
         {
             var process = new Process
diff --git a/Netch/Utils/Utils.cs b/Netch/Utils/Utils.cs
index 107bbbe3..5bc6c944 100644
--- a/Netch/Utils/Utils.cs
+++ b/Netch/Utils/Utils.cs
@@ -114,24 +114,6 @@ namespace Netch.Utils
             }
         }
 
-        public static void KillProcessByName(string name)
-        {
-            try
-            {
-                foreach (var p in Process.GetProcessesByName(name))
-                    if (p.MainModule != null && p.MainModule.FileName.StartsWith(Global.NetchDir))
-                        p.Kill();
-            }
-            catch (Win32Exception e)
-            {
-                Logging.Error($"结束进程 {name} 错误：" + e.Message);
-            }
-            catch (Exception)
-            {
-                // ignored
-            }
-        }
-
         public static string GetFileVersion(string file)
         {
             return File.Exists(file) ? FileVersionInfo.GetVersionInfo(file).FileVersion : string.Empty;