diff --git a/.vscode/settings.json b/.vscode/settings.json
index eaca38c..bc93b49 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -147,7 +147,8 @@
         "qxmlstreamwriter": "cpp",
         "qgraphicsdropshadoweffect": "cpp",
         "qpushbutton": "cpp",
-        "qpainter": "cpp"
+        "qpainter": "cpp",
+        "qdialog": "cpp"
     },
     "editor.tokenColorCustomizations": {
         "textMateRules": [
diff --git a/ClientCore/ClientCore.cpp b/ClientCore/ClientCore.cpp
index fdf166e..7b8e1ee 100644
--- a/ClientCore/ClientCore.cpp
+++ b/ClientCore/ClientCore.cpp
@@ -82,6 +82,29 @@ void ClientCore::onDisconnected()
     emit sigDisconnect();
 }
 
+void ClientCore::handleAsk(QSharedPointer<FrameBuffer> frame)
+{
+    InfoMsg msg = infoUnpack<InfoMsg>(frame->data);
+    // TODO: 处理询问请求
+    if (msg.command == STRMSG_REQUEST_CHECK_FILE_EXIST) {
+        InfoMsg ans;
+        ans.command = STRMSG_ANSWER_CHECK_FILE_EXIST;
+        for (const auto& filePath : msg.list) {
+            if (!Util::FileExist(filePath)) {
+                ans.list.append(filePath);
+            }
+        }
+        if (!Send<InfoMsg>(ans, FBT_MSGINFO_ANSWER, frame->fid)) {
+            auto logMsg = tr("给") + frame->fid + tr("返回检查文件存在性消息失败。");
+            qCritical() << logMsg;
+            return;
+        }
+        return;
+    }
+    // 未知信息
+    qWarning() << QString(tr("未知询问信息类型：%1")).arg(msg.command);
+}
+
 void ClientCore::UseFrame(QSharedPointer<FrameBuffer> frame)
 {
     switch (frame->type) {
@@ -182,7 +205,7 @@ void ClientCore::UseFrame(QSharedPointer<FrameBuffer> frame)
         break;
     }
     case FBT_MSGINFO_ASK: {
-        emit sigMsgAsk(frame);
+        handleAsk(frame);
         break;
     }
     case FBT_MSGINFO_ANSWER: {
diff --git a/ClientCore/ClientCore.h b/ClientCore/ClientCore.h
index bb700b6..33aa6a6 100644
--- a/ClientCore/ClientCore.h
+++ b/ClientCore/ClientCore.h
@@ -89,6 +89,7 @@ signals:
 private:
     void onReadyRead();
     void onDisconnected();
+    void handleAsk(QSharedPointer<FrameBuffer> frame);
 
 private:
     void UseFrame(QSharedPointer<FrameBuffer> frame);
diff --git a/Gui/Form/Loading.cpp b/Gui/Form/Loading.cpp
index ce6be89..033bd9f 100644
--- a/Gui/Form/Loading.cpp
+++ b/Gui/Form/Loading.cpp
@@ -106,8 +106,11 @@ void LoadingDialog::moveToCenter(QWidget* pParent)
  */
 void LoadingDialog::cancelBtnClicked()
 {
-    emit cancelWaiting();
-    this->done(USER_CANCEL);
+    if (isShow_) {
+        isShow_ = false;
+        emit cancelWaiting();
+        this->done(USER_CANCEL);
+    }
 }
 
 /**
@@ -129,6 +132,12 @@ void LoadingDialog::paintEvent(QPaintEvent* event)
     QWidget::paintEvent(event);
 }
 
+int LoadingDialog::exec()
+{
+    isShow_ = true;
+    return QDialog::exec();
+}
+
 LoadingDialog::~LoadingDialog()
 {
     delete m_pLoadingMovie;
diff --git a/Gui/Form/Loading.h b/Gui/Form/Loading.h
index 9af0c81..783eb6f 100644
--- a/Gui/Form/Loading.h
+++ b/Gui/Form/Loading.h
@@ -23,16 +23,19 @@ public:
     // 移动到指定窗口中间显示
     void moveToCenter(QWidget* pParent);
 
+public:
+    int exec() override;
+
 protected:
     void paintEvent(QPaintEvent* event) override;
 
 private:
     void initUi();
-    
+
 Q_SIGNALS:
     void cancelWaiting();
 
-private slots:
+public slots:
     void cancelBtnClicked();
 
 private:
@@ -40,6 +43,7 @@ private:
     QLabel* m_pMovieLabel;
     QMovie* m_pLoadingMovie;
     QLabel* m_pTipsLabel;
+    bool isShow_{};
     QPushButton* m_pCancelBtn;
 };
 #endif   // LOADINGDIALOG_H
\ No newline at end of file
diff --git a/Gui/Form/Transform.cpp b/Gui/Form/Transform.cpp
index dcf0331..7d07554 100644
--- a/Gui/Form/Transform.cpp
+++ b/Gui/Form/Transform.cpp
@@ -1,5 +1,6 @@
 #include "Transform.h"
 
+#include <QFileInfo>
 #include <QMessageBox>
 
 #include "ui_Transform.h"
@@ -146,3 +147,105 @@ void TransForm::closeEvent(QCloseEvent* event)
     exis_ = true;
     QDialog::closeEvent(event);
 }
+
+CheckCondition::CheckCondition(QObject* parent) : QThread(parent)
+{
+}
+
+void CheckCondition::SetClientCore(ClientCore* clientCore)
+{
+    clientCore_ = clientCore;
+}
+
+void CheckCondition::SetTasks(const QVector<TransTask>& tasks)
+{
+    tasks_ = tasks;
+}
+
+void CheckCondition::recvFrame(QSharedPointer<FrameBuffer> frame)
+{
+    InfoMsg info = infoUnpack<InfoMsg>(frame->data);
+    if (info.command == STRMSG_ANSWER_CHECK_FILE_EXIST) {
+        remoteNotExits_ = info.list;
+        qInfo() << tr("检查结束，远端不存在的文件数：") << remoteNotExits_.size();
+        msg_ = info.command;
+        return;
+    }
+    msg_ = tr("收到未知信息，认为判断失败：") + info.command;
+    qInfo() << msg_;
+}
+
+void CheckCondition::interrupCheck()
+{
+    if (!isAlreadyInter_) {
+        isAlreadyInter_ = true;
+        qWarning() << tr("中断文件校验......");
+        emit sigCheckOver();
+    }
+}
+
+void CheckCondition::run()
+{
+    qInfo() << tr("开始文件校验......");
+
+    resultMsgMap_.clear();
+    checkRet_.clear();
+    isRun_ = true;
+    msg_.clear();
+    isAlreadyInter_ = false;
+
+    // 先检查本地文件是否存在
+    for (const auto& task : tasks_) {
+        if (task.isUpload && !Util::FileExist(task.localPath)) {
+            resultMsgMap_[CCR_CHECK_LOCAL_NOT_EXIT].push_back(task.localPath);
+            if (!checkRet_.contains(CCR_CHECK_LOCAL_NOT_EXIT)) {
+                checkRet_.push_back(CCR_CHECK_LOCAL_NOT_EXIT);
+            }
+        }
+        if (!task.isUpload && Util::FileExist(task.localPath)) {
+            resultMsgMap_[CCR_CHECK_LOCAL_EXIT].push_back(task.localPath);
+            if (!checkRet_.contains(CCR_CHECK_LOCAL_EXIT)) {
+                checkRet_.push_back(CCR_CHECK_LOCAL_EXIT);
+            }
+        }
+    }
+
+    // 再检查远程文件是否存在
+    InfoMsg msg;
+    msg.command = STRMSG_REQUEST_CHECK_FILE_EXIST;
+    for (const auto& task : tasks_) {
+        msg.list.push_back(task.remotePath);
+    }
+
+    auto f = clientCore_->GetBuffer(msg, FBT_MSGINFO_ASK, clientCore_->GetRemoteID());
+    if (!ClientCore::syncInvoke(clientCore_, f)) {
+        auto errMsg = tr("检查远程文件存在性数据发送失败。");
+        if (!checkRet_.contains(CCR_CHECK_FAILED)) {
+            checkRet_.push_back(CCR_CHECK_FAILED);
+            resultMsgMap_[CCR_CHECK_FAILED].push_back(errMsg);
+        }
+        emit sigCheckOver();
+        qCritical() << errMsg;
+        return;
+    }
+    while (isRun_) {
+        QThread::msleep(10);
+        if (msg_.isEmpty()) {
+            continue;
+        }
+        if (msg_ != STRMSG_ANSWER_CHECK_FILE_EXIST) {
+            if (!checkRet_.contains(CCR_CHECK_FAILED)) {
+                checkRet_.push_back(CCR_CHECK_FAILED);
+                resultMsgMap_[CCR_CHECK_FAILED].push_back(msg_);
+            }
+        } else {
+            if (!checkRet_.contains(CCR_CHECK_PASSED)) {
+                checkRet_.push_back(CCR_CHECK_PASSED);
+            }
+        }
+        break;
+    }
+    isAlreadyInter_ = true;
+    emit sigCheckOver();
+    qInfo() << tr("文件校验结束......");
+}
diff --git a/Gui/Form/Transform.h b/Gui/Form/Transform.h
index f672979..bc73d9f 100644
--- a/Gui/Form/Transform.h
+++ b/Gui/Form/Transform.h
@@ -6,6 +6,7 @@
 #include <QDialog>
 #include <QFile>
 #include <QThread>
+#include <unordered_map>
 
 namespace Ui {
 class TransForm;
@@ -33,7 +34,7 @@ signals:
     void sigTaskNum(const QString& data);
 
 private:
-	void setProgress(double val);
+    void setProgress(double val);
     void handleFailed();
     void handleDone();
     void handleUI(const TransTask& task);
@@ -41,12 +42,12 @@ private:
 
 protected:
     void showEvent(QShowEvent* event) override;
-    void closeEvent(QCloseEvent* event) override;   
+    void closeEvent(QCloseEvent* event) override;
 
 private:
-    bool exis_{ false };
+    bool exis_{false};
     TranFromTh* workTh_{};
-    qint32 curTaskNum_{ 0 };
+    qint32 curTaskNum_{0};
     QVector<TransTask> tasks_;
     FileTrans* fileTrans_{};
     ClientCore* clientCore_{};
@@ -61,6 +62,7 @@ public:
     explicit TranFromTh(TransForm* tf, QObject* parent = nullptr) : QThread(parent), tf_(tf)
     {
     }
+
 protected:
     void run() override
     {
@@ -73,4 +75,47 @@ private:
     TransForm* tf_;
 };
 
-#endif   // TRANSFORM_H
+enum CondCheckResult {
+    CCR_NO_CHECK = 0,
+    CCR_CHECK_PASSED,
+    CCR_CHECK_FAILED,
+    CCR_CHECK_INTERRUPT,
+    CCR_CHECK_LOCAL_EXIT,
+    CCR_CHECK_REMOTE_EXIT,
+    CCR_CHECK_LOCAL_NOT_EXIT,
+    CCR_CHECK_REMOTE_NOT_EXIT
+};
+
+class CheckCondition : public QThread
+{
+    Q_OBJECT
+
+public:
+    CheckCondition(QObject* parent = nullptr);
+
+public:
+    void SetClientCore(ClientCore* clientCore);
+    void SetTasks(const QVector<TransTask>& tasks);
+
+Q_SIGNALS:
+    void sigCheckOver();
+
+public Q_SLOTS:
+    void interrupCheck();
+    void recvFrame(QSharedPointer<FrameBuffer> frame);
+
+protected:
+    void run() override;
+
+private:
+    QString msg_;
+    bool isRun_;
+    bool isAlreadyInter_;
+    QVector<TransTask> tasks_;
+    ClientCore* clientCore_{};
+    QVector<QString> remoteNotExits_;
+    QVector<CondCheckResult> checkRet_;
+    std::unordered_map<CondCheckResult, QVector<QString>> resultMsgMap_;
+};
+
+#endif // TRANSFORM_H
\ No newline at end of file
diff --git a/Gui/frelayGUI.cpp b/Gui/frelayGUI.cpp
index 56bf2af..3bbeaf3 100644
--- a/Gui/frelayGUI.cpp
+++ b/Gui/frelayGUI.cpp
@@ -1,5 +1,6 @@
 #include "frelayGUI.h"
 
+#include <Form/Loading.h>
 #include <QLabel>
 #include <QScreen>
 #include <QSplitter>
@@ -35,7 +36,7 @@ frelayGUI::frelayGUI(QWidget* parent) : QDialog(parent), ui(new Ui::frelayGUI)
     // QLabel* permanent = new QLabel(this);
     // permanent->setFrameStyle(QFrame::Box | QFrame::Sunken);
     // permanent->setText(QString("%1 on %2").arg(VERSION_GIT_COMMIT, VERSION_GIT_BRANCH));
-    //this->statusBar()->addPermanentWidget(permanent);
+    // this->statusBar()->addPermanentWidget(permanent);
 }
 
 frelayGUI::~frelayGUI()
@@ -142,6 +143,22 @@ void frelayGUI::HandleTask(const QVector<TransTask>& tasks)
         return;
     }
     transform_->SetTasks(tasks);
+
+    // 检查文件
+    CheckCondition checkThread(this);
+    checkThread.SetTasks(tasks);
+    checkThread.SetClientCore(clientCore_);
+
+    LoadingDialog checking(this);
+    checking.setTipsText("正在检查文件...");
+
+    connect(&checkThread, &CheckCondition::sigCheckOver, &checking, &LoadingDialog::cancelBtnClicked);
+    connect(&checking, &LoadingDialog::cancelWaiting, &checkThread, &CheckCondition::interrupCheck);
+    connect(clientCore_, &ClientCore::sigMsgAnswer, &checkThread, &CheckCondition::recvFrame);
+
+    checkThread.start();
+    checking.exec();
+
     transform_->exec();
 }
 
diff --git a/Protocol/Protocol.h b/Protocol/Protocol.h
index cc03af2..fcc3b57 100644
--- a/Protocol/Protocol.h
+++ b/Protocol/Protocol.h
@@ -42,9 +42,8 @@ enum FrameBufferType : uint16_t {
 };
 
 // 字符串标识
-#define STRMSG_CHECK_FILE_EXIST "checkFileExist"
-#define STRMSG_FILE_EXIST "fileExist"
-#define STRMSG_FILE_NOT_EXIST "fileNotExist"
+#define STRMSG_REQUEST_CHECK_FILE_EXIST "requestCheckFileExist"
+#define STRMSG_ANSWER_CHECK_FILE_EXIST "answerCheckFileExist"
 
 struct FrameBuffer {
     QByteArray data;
diff --git a/Util/Util.cpp b/Util/Util.cpp
index 46e84fb..bbfd52c 100644
--- a/Util/Util.cpp
+++ b/Util/Util.cpp
@@ -125,6 +125,16 @@ QString Util::GetVersion()
     return ver;
 }
 
+bool Util::FileExist(const QString& path)
+{
+    return QFile::exists(path);
+}
+
+bool Util::DirExist(const QString& path)
+{
+    return QDir(path).exists();
+}
+
 QString DirFileHelper::GetErr() const
 {
     return QString();
diff --git a/Util/Util.h b/Util/Util.h
index 95cb3b1..2d116b0 100644
--- a/Util/Util.h
+++ b/Util/Util.h
@@ -49,6 +49,8 @@ public:
     static QString GetCurConfigPath(const QString& sub);
     static void ConsoleMsgHander(QtMsgType type, const QMessageLogContext& context, const QString& msg);
     static QString GetVersion();
+    static bool FileExist(const QString& path);
+    static bool DirExist(const QString& path);
 };
 
 class DirFileHelper : public QObject