diff --git a/WindowsFormsApp6/MainForm.cs b/WindowsFormsApp6/MainForm.cs
index a1ea59e..e3c4f62 100644
--- a/WindowsFormsApp6/MainForm.cs
+++ b/WindowsFormsApp6/MainForm.cs
@@ -59,42 +59,159 @@ namespace WindowsFormsApp6
             _readTimer.Interval = 100; // 100ms检查一次信号量
             _readTimer.Tick += ReadTimer_Tick;
 
-            // 配置串口参数
-            _serialPort = new SerialPort
+            // 尝试打开默认串口
+            if (!TryOpenSerialPort("COM2"))
             {
-                PortName = "COM2",
-                BaudRate = 19200,
-                DataBits = 8,
-                Parity = Parity.None,
-                StopBits = StopBits.One,
-                ReadTimeout = 500,
-                WriteTimeout = 500,
-                RtsEnable = false,
-                DtrEnable = false
-            };
+                // 如果默认串口失败，弹出端口选择对话框
+                ShowPortSelectionDialog();
+            }
+        }
 
+        /// <summary>
+        /// 尝试打开指定的串口
+        /// </summary>
+        private bool TryOpenSerialPort(string portName)
+        {
             try
             {
-                // 打开串口
-                if (!_serialPort.IsOpen)
+                // 如果已有串口打开，先关闭
+                if (_serialPort != null && _serialPort.IsOpen)
                 {
-                    _serialPort.Open();
-                    
-                    // 创建Modbus RTU主站
-                    _modbusMaster = ModbusSerialMaster.CreateRtu(_serialPort);
-                    _modbusMaster.Transport.WaitToRetryMilliseconds = 200;
-                    _modbusMaster.Transport.Retries = 1;
-                    _modbusMaster.Transport.ReadTimeout = 500;
-                    
-                    // 启动定时读取
-                    _readTimer.Start();
-                    
-                    ShowInfoMsg("数据采集器初始化成功");
+                    _serialPort.Close();
+                    _serialPort.Dispose();
                 }
+
+                // 配置串口参数
+                _serialPort = new SerialPort
+                {
+                    PortName = portName,
+                    BaudRate = 19200,
+                    DataBits = 8,
+                    Parity = Parity.None,
+                    StopBits = StopBits.One,
+                    ReadTimeout = 500,
+                    WriteTimeout = 500,
+                    RtsEnable = false,
+                    DtrEnable = false
+                };
+
+                // 打开串口
+                _serialPort.Open();
+                
+                // 创建Modbus RTU主站
+                _modbusMaster = ModbusSerialMaster.CreateRtu(_serialPort);
+                _modbusMaster.Transport.WaitToRetryMilliseconds = 200;
+                _modbusMaster.Transport.Retries = 1;
+                _modbusMaster.Transport.ReadTimeout = 500;
+                
+                // 启动定时读取
+                _readTimer.Start();
+                
+                ShowInfoMsg($"串口 {portName} 初始化成功");
+                return true;
             }
             catch (Exception ex)
             {
-                ShowErrorMsg($"串口/Modbus初始化失败：{ex.Message}");
+                System.Diagnostics.Debug.WriteLine($"打开串口 {portName} 失败：{ex.Message}");
+                return false;
+            }
+        }
+
+        /// <summary>
+        /// 显示端口选择对话框
+        /// </summary>
+        private void ShowPortSelectionDialog()
+        {
+            // 获取当前计算机所有可用串口
+            string[] ports = SerialPort.GetPortNames();
+
+            if (ports == null || ports.Length == 0)
+            {
+                ShowErrorMsg("未检测到可用的串口，请检查串口连接。");
+                return;
+            }
+
+            // 创建端口选择对话框
+            Form portDialog = new Form
+            {
+                Text = "选择串口",
+                Width = 350,
+                Height = 200,
+                StartPosition = FormStartPosition.CenterParent,
+                FormBorderStyle = FormBorderStyle.FixedDialog,
+                MaximizeBox = false,
+                MinimizeBox = false
+            };
+
+            Label label = new Label
+            {
+                Text = "串口初始化失败，请选择可用的串口：",
+                Location = new Point(20, 20),
+                AutoSize = true
+            };
+
+            ComboBox comboBox = new ComboBox
+            {
+                Location = new Point(20, 50),
+                Width = 290,
+                DropDownStyle = ComboBoxStyle.DropDownList
+            };
+            comboBox.Items.AddRange(ports);
+            if (comboBox.Items.Count > 0)
+            {
+                comboBox.SelectedIndex = 0;
+            }
+
+            Button btnOK = new Button
+            {
+                Text = "确定",
+                DialogResult = DialogResult.OK,
+                Location = new Point(140, 100),
+                Width = 80
+            };
+
+            Button btnCancel = new Button
+            {
+                Text = "取消",
+                DialogResult = DialogResult.Cancel,
+                Location = new Point(230, 100),
+                Width = 80
+            };
+
+            portDialog.Controls.AddRange(new Control[] { label, comboBox, btnOK, btnCancel });
+            portDialog.AcceptButton = btnOK;
+            portDialog.CancelButton = btnCancel;
+
+            // 显示对话框
+            if (portDialog.ShowDialog(this) == DialogResult.OK)
+            {
+                string selectedPort = comboBox.SelectedItem?.ToString();
+                if (!string.IsNullOrEmpty(selectedPort))
+                {
+                    if (TryOpenSerialPort(selectedPort))
+                    {
+                        // 成功打开
+                        return;
+                    }
+                    else
+                    {
+                        // 选择的端口也失败，询问是否重新选择
+                        var result = MessageBox.Show(
+                            $"打开串口 {selectedPort} 失败，是否重新选择？",
+                            "错误",
+                            MessageBoxButtons.YesNo,
+                            MessageBoxIcon.Error);
+
+                        if (result == DialogResult.Yes)
+                        {
+                            ShowPortSelectionDialog(); // 递归调用，重新选择
+                        }
+                    }
+                }
+            }
+            else
+            {
+                ShowErrorMsg("未选择串口，数据采集功能将不可用。");
             }
         }