diff --git a/connector/native/app_macos.mm b/connector/native/app_macos.mm
index 0df8937..a1ea6df 100644
--- a/connector/native/app_macos.mm
+++ b/connector/native/app_macos.mm
@@ -79,13 +79,15 @@ using connector::ConnectorService;
 
 - (void)refreshStatus:(id)sender {
   (void)sender;
-  self.connectionButton.title = self.service && self.service->running() ? @"断开连接" : @"启动连接";
-  if (self.startupError.length > 0) {
+  const BOOL ownsPort = self.service && self.service->running();
+  const BOOL portOccupied = ownsPort || connector::connector_port_in_use();
+  self.connectionButton.title = portOccupied ? @"停止连接" : @"启动连接";
+  if (self.startupError.length > 0 && !portOccupied) {
     self.statusLabel.stringValue = [@"● 连接器未启动 · " stringByAppendingString:self.startupError];
     self.statusLabel.textColor = NSColor.systemRedColor;
     return;
   }
-  if (!self.service || !self.service->running()) {
+  if (!portOccupied) {
     self.statusLabel.stringValue = @"● 连接器已断开";
     self.statusLabel.textColor = NSColor.secondaryLabelColor;
     return;
@@ -93,6 +95,11 @@ using connector::ConnectorService;
   const std::string spine = connector::find_spine_executable();
   const BOOL showPathControls = spine.empty();
   for (NSView* view in self.pathControls) view.hidden = !showPathControls;
+  if (!ownsPort) {
+    self.statusLabel.stringValue = @"● 端口 27843 正在运行 · 可停止连接";
+    self.statusLabel.textColor = NSColor.systemGreenColor;
+    return;
+  }
   self.statusLabel.stringValue = spine.empty() ? @"● 连接器运行中 · 未找到 Spine" : @"● 连接器运行中 · Spine 已就绪";
   self.statusLabel.textColor = spine.empty() ? NSColor.systemOrangeColor : NSColor.systemGreenColor;
 }
@@ -102,6 +109,10 @@ using connector::ConnectorService;
   if (self.service && self.service->running()) {
     self.service->stop();
     self.startupError = @"";
+  } else if (connector::connector_port_in_use()) {
+    std::string error;
+    connector::stop_connector_port(error);
+    self.startupError = [NSString stringWithUTF8String:error.c_str()];
   } else if (self.service) {
     std::string error;
     self.service->start(error);
diff --git a/connector/native/app_windows.cpp b/connector/native/app_windows.cpp
index 44ec0ed..ef918cc 100644
--- a/connector/native/app_windows.cpp
+++ b/connector/native/app_windows.cpp
@@ -141,13 +141,18 @@ std::wstring field_text(HWND field) {
 }
 
 void refresh_status() {
+  const bool owns_port = service.running();
+  const bool port_occupied = owns_port || connector::connector_port_in_use();
   std::wstring status;
-  if (!startup_error.empty()) {
+  if (!startup_error.empty() && !port_occupied) {
     status = L"● 连接器未启动 · " + wide(startup_error);
     status_color = kErrorText;
-  } else if (!service.running()) {
+  } else if (!port_occupied) {
     status = L"● 连接器已断开";
     status_color = kSecondaryText;
+  } else if (!owns_port) {
+    status = L"● 端口 27843 正在运行 · 可停止连接";
+    status_color = kSuccessText;
   } else if (connector::find_spine_executable().empty()) {
     status = L"● 连接器运行中 · 未找到 Spine";
     status_color = kWarningText;
@@ -157,7 +162,7 @@ void refresh_status() {
   }
   SetWindowTextW(status_label, status.c_str());
   InvalidateRect(status_label, nullptr, TRUE);
-  SetWindowTextW(connection_button, service.running() ? L"断开连接" : L"启动连接");
+  SetWindowTextW(connection_button, port_occupied ? L"停止连接" : L"启动连接");
   const bool show_path = connector::find_spine_executable().empty();
   for (HWND control : {path_label, path_field, browse_button, automatic_button, save_button}) {
     if (control) ShowWindow(control, show_path ? SW_SHOW : SW_HIDE);
@@ -246,6 +251,9 @@ LRESULT CALLBACK window_proc(HWND window, UINT message, WPARAM wparam, LPARAM lp
           if (service.running()) {
             service.stop();
             startup_error.clear();
+          } else if (connector::connector_port_in_use()) {
+            startup_error.clear();
+            connector::stop_connector_port(startup_error);
           } else {
             startup_error.clear();
             service.start(startup_error);
diff --git a/connector/native/platform.hpp b/connector/native/platform.hpp
index bdae1ed..78b2bd6 100644
--- a/connector/native/platform.hpp
+++ b/connector/native/platform.hpp
@@ -20,6 +20,10 @@ std::filesystem::path to_path(const std::string& value);
 std::string platform_name();
 std::string find_spine_executable();
 bool valid_spine_executable(const std::string& path);
+// 查询/释放连接器固定使用的本地端口。释放操作针对当前监听进程，
+// 使用户可以从新打开的连接器窗口停止遗留实例或其他占用者。
+bool connector_port_in_use();
+bool stop_connector_port(std::string& error);
 ProcessResult run_process(const std::string& executable,
                           const std::vector<std::string>& arguments,
                           const std::filesystem::path& working_directory,
diff --git a/connector/native/process_posix.cpp b/connector/native/process_posix.cpp
index 56c28cf..4c0bd77 100644
--- a/connector/native/process_posix.cpp
+++ b/connector/native/process_posix.cpp
@@ -5,6 +5,8 @@
 #include <chrono>
 #include <csignal>
 #include <fcntl.h>
+#include <set>
+#include <sstream>
 #include <stdexcept>
 #include <sys/types.h>
 #include <sys/wait.h>
@@ -12,6 +14,38 @@
 #include <unistd.h>
 
 namespace connector {
+namespace {
+
+constexpr unsigned short kConnectorPort = 27843;
+
+std::filesystem::path lsof_path() {
+  for (const char* candidate : {"/usr/sbin/lsof", "/usr/bin/lsof"}) {
+    if (std::filesystem::exists(candidate)) return candidate;
+  }
+  return {};
+}
+
+std::set<pid_t> connector_port_pids() {
+  const std::filesystem::path executable = lsof_path();
+  if (executable.empty()) return {};
+  const ProcessResult result = run_process(executable.string(),
+      {"-nP", "-tiTCP:" + std::to_string(kConnectorPort), "-sTCP:LISTEN"}, {}, 3);
+  if (result.timed_out || (result.exit_code != 0 && result.exit_code != 1)) return {};
+  std::set<pid_t> pids;
+  std::istringstream lines(result.output);
+  std::string line;
+  while (std::getline(lines, line)) {
+    try {
+      const long value = std::stol(line);
+      if (value > 0) pids.insert(static_cast<pid_t>(value));
+    } catch (...) {
+      // lsof 可能输出诊断信息；只接受纯数字 PID。
+    }
+  }
+  return pids;
+}
+
+}  // namespace
 
 ProcessResult run_process(const std::string& executable,
                           const std::vector<std::string>& arguments,
@@ -70,6 +104,46 @@ ProcessResult run_process(const std::string& executable,
   return result;
 }
 
+bool connector_port_in_use() {
+  return !connector_port_pids().empty();
+}
+
+bool stop_connector_port(std::string& error) {
+  const std::set<pid_t> pids = connector_port_pids();
+  if (pids.empty()) {
+    error.clear();
+    return true;
+  }
+  for (const pid_t pid : pids) {
+    if (pid == getpid()) {
+      error = "无法从外部停止当前连接器进程";
+      return false;
+    }
+    if (kill(pid, SIGTERM) != 0) {
+      error = "无法停止占用端口 27843 的进程，请检查系统权限";
+      return false;
+    }
+  }
+  const auto deadline = std::chrono::steady_clock::now() + std::chrono::seconds(3);
+  while (std::chrono::steady_clock::now() < deadline) {
+    if (!connector_port_in_use()) {
+      error.clear();
+      return true;
+    }
+    std::this_thread::sleep_for(std::chrono::milliseconds(50));
+  }
+  for (const pid_t pid : pids) {
+    if (kill(pid, 0) == 0) kill(pid, SIGKILL);
+  }
+  std::this_thread::sleep_for(std::chrono::milliseconds(100));
+  if (connector_port_in_use()) {
+    error = "已请求停止进程，但端口 27843 仍未释放";
+    return false;
+  }
+  error.clear();
+  return true;
+}
+
 }  // namespace connector
 
 #endif
diff --git a/connector/native/process_windows.cpp b/connector/native/process_windows.cpp
index 6625d8c..1b3a034 100644
--- a/connector/native/process_windows.cpp
+++ b/connector/native/process_windows.cpp
@@ -1,17 +1,24 @@
 #ifdef _WIN32
 
 #define NOMINMAX
+#define WIN32_LEAN_AND_MEAN
+#include <winsock2.h>
 #include <windows.h>
+#include <iphlpapi.h>
 
 #include "platform.hpp"
 
 #include <chrono>
+#include <set>
 #include <stdexcept>
 #include <thread>
+#include <vector>
 
 namespace connector {
 namespace {
 
+constexpr unsigned short kConnectorPort = 27843;
+
 std::wstring wide(const std::string& value) {
   if (value.empty()) return {};
   const int size = MultiByteToWideChar(CP_UTF8, 0, value.data(), static_cast<int>(value.size()), nullptr, 0);
@@ -35,6 +42,26 @@ std::wstring quote(const std::string& value) {
   return result + L'\"';
 }
 
+std::set<DWORD> connector_port_pids() {
+  DWORD size = 0;
+  DWORD result = GetExtendedTcpTable(nullptr, &size, FALSE, AF_INET,
+                                     TCP_TABLE_OWNER_PID_LISTENER, 0);
+  if (result != ERROR_INSUFFICIENT_BUFFER || size == 0) return {};
+  std::vector<unsigned char> storage(size);
+  result = GetExtendedTcpTable(storage.data(), &size, FALSE, AF_INET,
+                               TCP_TABLE_OWNER_PID_LISTENER, 0);
+  if (result != NO_ERROR) return {};
+  const auto* table = reinterpret_cast<const MIB_TCPTABLE_OWNER_PID*>(storage.data());
+  std::set<DWORD> pids;
+  for (DWORD index = 0; index < table->dwNumEntries; ++index) {
+    const auto& row = table->table[index];
+    if (ntohs(static_cast<u_short>(row.dwLocalPort)) == kConnectorPort && row.dwOwningPid != 0) {
+      pids.insert(row.dwOwningPid);
+    }
+  }
+  return pids;
+}
+
 }  // namespace
 
 ProcessResult run_process(const std::string& executable,
@@ -93,6 +120,46 @@ ProcessResult run_process(const std::string& executable,
   return result;
 }
 
+bool connector_port_in_use() {
+  return !connector_port_pids().empty();
+}
+
+bool stop_connector_port(std::string& error) {
+  const std::set<DWORD> pids = connector_port_pids();
+  if (pids.empty()) {
+    error.clear();
+    return true;
+  }
+  for (const DWORD pid : pids) {
+    if (pid == GetCurrentProcessId()) {
+      error = "无法从外部停止当前连接器进程";
+      return false;
+    }
+    HANDLE process = OpenProcess(PROCESS_TERMINATE | SYNCHRONIZE, FALSE, pid);
+    if (!process) {
+      error = "无法停止占用端口 27843 的进程，请以管理员身份运行后重试";
+      return false;
+    }
+    const BOOL stopped = TerminateProcess(process, 0);
+    if (stopped) WaitForSingleObject(process, 3000);
+    CloseHandle(process);
+    if (!stopped) {
+      error = "停止占用端口 27843 的进程失败";
+      return false;
+    }
+  }
+  const auto deadline = std::chrono::steady_clock::now() + std::chrono::seconds(3);
+  while (std::chrono::steady_clock::now() < deadline) {
+    if (!connector_port_in_use()) {
+      error.clear();
+      return true;
+    }
+    std::this_thread::sleep_for(std::chrono::milliseconds(50));
+  }
+  error = "进程已停止，但端口 27843 仍未释放";
+  return false;
+}
+
 }  // namespace connector
 
 #endif