diff --git a/src/DSCAnalysisTool.pro b/src/DSCAnalysisTool.pro
index 7854328..4fef804 100644
--- a/src/DSCAnalysisTool.pro
+++ b/src/DSCAnalysisTool.pro
@@ -9,7 +9,7 @@ CONFIG+=precompile_header
 PRECOMPILED_HEADER=stable.h
 
 #
-VERSION = 1.3.0
+VERSION = 1.3.4
 # 设置目标文件名，包含版本号
 TARGET = DSCAnalysisTool_$${VERSION}
 
diff --git a/src/mainwindow.cpp b/src/mainwindow.cpp
index a2cfaaf..2c8b0f0 100644
--- a/src/mainwindow.cpp
+++ b/src/mainwindow.cpp
@@ -127,6 +127,8 @@ void MainWindow::connections() {
     connect(SerialPort::instance(), &SerialPort::sigStartExperiment,
             this, &MainWindow::slotStartExperiment);
 
+    connect(SerialPort::instance(), &SerialPort::sigDeviceDisconnected,
+            this, &MainWindow::slotDeviceDisconnected);
 #endif
 
     // mode
@@ -422,7 +424,7 @@ void MainWindow::startExperimentByDeviceInfo() {
     Global::_mode                  = Global::Mode::Experiment;
     _manuallyStopTheExperimentFlag = false;
     _centralWidget->startExperiment();
-    
+
     // 实验开始，清除上一个实验所有数据。
     Global::clearExperimentData();
 }
@@ -594,7 +596,7 @@ void MainWindow::on_actionPeakSynthesisAnalysis_triggered() {
 
 void MainWindow::on_actionClearAllData_triggered() {
     // 实验过程中，不允许清除数据。
-    if(Global::_mode == Global::Mode::Experiment) {
+    if (Global::_mode == Global::Mode::Experiment) {
         return;
     }
 
@@ -805,3 +807,19 @@ void MainWindow::showMesgBox(const QString str) {
         isShow = false;
     }
 }
+
+void MainWindow::slotDeviceDisconnected() {
+ //   logde<<"slotDeviceDisconnected...1";
+    // 如果当前是实验模式时，需要先停止实验。
+    if (SerialPort::instance()->isOpen()) {
+  //      logde<<"slotDeviceDisconnected...2";
+        // ui更新，断开连接
+        ui->actionConnectToDev->setIcon(QIcon(":/images/connect.png"));
+        ui->actionConnectToDev->setText("连接设备");
+        // 停止实验
+        on_actionStop_triggered();
+
+        SerialPort::instance()->closeSp();
+
+    }
+}
diff --git a/src/mainwindow.h b/src/mainwindow.h
index 0f166be..711e74a 100644
--- a/src/mainwindow.h
+++ b/src/mainwindow.h
@@ -43,6 +43,8 @@ public slots:
     void slotOITAutoAnalysis(const double,const double);
 
     void slotStartExperiment();
+
+    void slotDeviceDisconnected();
 protected:
     void closeEvent(QCloseEvent *event) override;
 private slots:
diff --git a/src/serialport/serialport.cpp b/src/serialport/serialport.cpp
index 99b4c45..d9dd557 100644
--- a/src/serialport/serialport.cpp
+++ b/src/serialport/serialport.cpp
@@ -19,7 +19,13 @@ const u16 conVid = 1155;     // 0x0483
 const u16 conPid = 22336;    // 0x5740
 
 SerialPort::SerialPort(QObject *parent)
-    : QObject(parent), _sp(new QSerialPort(this)) {
+    : QObject(parent), _sp(new QSerialPort(this)),
+      _portCheckTimer(new QTimer(this)) {
+    //
+    connect(_portCheckTimer, &QTimer::timeout,
+            this, &SerialPort::slotPortCheck);
+    _portCheckTimer->start(1000);    // 每秒检测一次
+
     //    displayPortInfo();
 
 #if 0
@@ -80,9 +86,13 @@ SerialPort::~SerialPort() {
     logde << "serialport destructor.";
 
     closeSp();
-
+    //
     delete _sp;
     _sp = nullptr;
+    //
+    _portCheckTimer->stop();
+    delete _portCheckTimer;
+    _portCheckTimer = nullptr;
 }
 
 void SerialPort::slotReadData() {
@@ -594,3 +604,22 @@ void SerialPort::slotCloseSp() {
         _sp->close();
     }
 }
+
+void SerialPort::slotPortCheck() {
+   // logde<<"slotPortCheck...";
+
+    foreach (const QSerialPortInfo &info, QSerialPortInfo::availablePorts()) {
+        u16 pid = info.productIdentifier();
+        u16 vid = info.vendorIdentifier();
+
+        if ((pid == conPid) && (vid == conVid)) {
+           // logde<<"slotPortCheck... device connected.";
+            return;
+        }
+    }
+    // Device disconnected
+    // logde<<"device disconnected.";
+    emit sigDeviceDisconnected();
+
+   // logde<<"slotPortCheck... device disconnected.";
+}
diff --git a/src/serialport/serialport.h b/src/serialport/serialport.h
index c64d9dd..e9dc82f 100644
--- a/src/serialport/serialport.h
+++ b/src/serialport/serialport.h
@@ -4,6 +4,7 @@
 #include <QObject>
 #include <QSerialPort>
 #include <QSerialPortInfo>
+#include <qtimer.h>
 
 #include "defines.h"
 #include "protocol.h"
@@ -36,12 +37,14 @@ signals:
     void sigUpdateStatusbarMsg(const QString &);
     void sigSaveExperimentalDataMsgBox();
     void sigStartExperiment();
+    void sigDeviceDisconnected();
 public slots:
     void slotDeliverData(const QByteArray &);
     void slotSendData(const QByteArray &);
     void slotCloseSp();
 private slots:
     void slotReadData();
+    void slotPortCheck();
 private:
     void updateStatus(const CommonData &cd);
     void updateAxis();
@@ -52,6 +55,9 @@ private:
     SerialPort(QObject *parent = nullptr);
     QSerialPort *_sp;
     QByteArray _lastWriteBa;
+    
+    // port check
+    QTimer* _portCheckTimer = nullptr;
 };
 
-#endif // SERIALPORT_H
+#endif // SERIALPORT_H
\ No newline at end of file