diff --git a/backup-daemon/backup-daemon.pro b/backup-daemon/backup-daemon.pro
index 6e77156..c290d8b 100644
--- a/backup-daemon/backup-daemon.pro
+++ b/backup-daemon/backup-daemon.pro
@@ -29,6 +29,7 @@ HEADERS += \
     backupmanager_adaptor.h \
     mybackupmanager.h \
     mymountproxy.h \
+    myprocess/calcbackupsize.h \
     myprocess/mountbackupprocess.h \
     parsebackuplist.h \
     systembackupproxy.h \
@@ -44,6 +45,7 @@ SOURCES += \
         main.cpp \
         mybackupmanager.cpp \
         mymountproxy.cpp \
+        myprocess/calcbackupsize.cpp \
         myprocess/mountbackupprocess.cpp \
         parsebackuplist.cpp \
         systembackupproxy.cpp \
diff --git a/backup-daemon/myprocess/calcbackupsize.cpp b/backup-daemon/myprocess/calcbackupsize.cpp
new file mode 100644
index 0000000..4083365
--- /dev/null
+++ b/backup-daemon/myprocess/calcbackupsize.cpp
@@ -0,0 +1,101 @@
+#include "calcbackupsize.h"
+#include <QDebug>
+
+CalcBackupSize::CalcBackupSize(QObject* parent) :
+    QObject(parent),
+    m_process(new QProcess(this))
+{
+    connect(m_process, &QProcess::readyReadStandardError, this, [&]() {
+        QByteArray err = m_process->readAllStandardError();
+        qCritical("backup process error: %s", err.data());
+    });
+
+    connect(m_process, &QProcess::errorOccurred, this, [&](QProcess::ProcessError error) {
+        m_process->kill();
+    });
+
+    connect(m_process, SIGNAL(finished(int, QProcess::ExitStatus)), this, SLOT(getCalcResult(int, QProcess::ExitStatus)));
+}
+
+CalcBackupSize::~CalcBackupSize()
+{
+
+}
+
+/**
+ * @brief 计算备份大小，单位字节
+ * @param args rsync参数列表
+ * @param block 是否阻塞计算模式。默认true——阻塞计算模式
+ * @return block为true时返回值为待备份数据大小，单位字节；block为false时，默认返回0;
+ */
+qint64 CalcBackupSize::calcBackupSize(QStringList args, bool block)
+{
+    QString cmd("rsync ");
+    for (const QString& item : args) {
+       cmd += " ";
+       cmd += item;
+    }
+    qDebug() << cmd;
+
+    m_size = 0;
+
+    m_process->start("rsync", args);
+    if (!m_process->waitForStarted()) {
+        qCritical("rsync start failed");
+        return m_size;
+    }
+
+    if (block) {
+        m_process->waitForFinished();
+    }
+
+    return m_size;
+}
+
+/**
+ * @brief 解析结果
+ * @param exitCode
+ */
+void CalcBackupSize::getCalcResult(int exitCode, QProcess::ExitStatus)
+{
+    // 解析结果，结果内容样例如下：
+    /*
+    Number of files: 8 (reg: 4, dir: 4)
+    Number of created files: 7 (reg: 4, dir: 3)
+    Number of deleted files: 0
+    Number of regular files transferred: 4
+    Total file size: 20 bytes
+    Total transferred file size: 20 bytes
+    Literal data: 0 bytes
+    Matched data: 0 bytes
+    File list size: 0
+    File list generation time: 0.001 seconds
+    File list transfer time: 0.000 seconds
+    Total bytes sent: 248
+    Total bytes received: 43
+
+    sent 248 bytes  received 43 bytes  582.00 bytes/sec
+    total size is 20  speedup is 0.07 (DRY RUN)
+    */
+    QString out(m_process->readAll());
+    QStringList lines = out.split("\n");
+    for (QString& line : lines) {
+        line.trimmed();
+        // 获取文件夹数目
+        if (line.startsWith("Number of files:")) {
+            int indexOfLastColon = line.lastIndexOf(":");
+            int indexOfLastLable = line.lastIndexOf(")");
+            int numOfDirs = line.mid(indexOfLastColon+1, indexOfLastLable-indexOfLastColon).trimmed().toInt();
+            // 每个目录下还都有.和..，故总数还要*3
+            numOfDirs *= 3;
+            // ext4格式的目录本身要占用4K空间（4096）
+            m_size += numOfDirs * 4096;
+        }
+        if (line.startsWith("Total file size:")) {
+            m_size += line.replace("Total file size:", "").replace("bytes", "").trimmed().toLongLong();
+            break ;
+        }
+    }
+
+    emit calcFinished(m_size);
+}
diff --git a/backup-daemon/myprocess/calcbackupsize.h b/backup-daemon/myprocess/calcbackupsize.h
new file mode 100644
index 0000000..1850679
--- /dev/null
+++ b/backup-daemon/myprocess/calcbackupsize.h
@@ -0,0 +1,38 @@
+#ifndef CALCBACKUPSIZE_H
+#define CALCBACKUPSIZE_H
+
+#include <QStringList>
+#include <QProcess>
+
+#define GB (1024 * 1024 * 1024)
+#define MB (1024 * 1024)
+#define KB (1024)
+
+class CalcBackupSize : public QObject
+{
+    Q_OBJECT
+public:
+    CalcBackupSize(QObject* parent = nullptr);
+    ~CalcBackupSize();
+
+    /**
+     * @brief 计算备份大小，单位字节
+     * @param args rsync参数列表
+     * @param block 是否阻塞计算模式。默认true——阻塞计算模式
+     * @return block为true时返回值为待备份数据大小，单位字节；block为false时，默认返回0
+     */
+    qint64 calcBackupSize(QStringList args, bool block = true);
+
+signals:
+    void calcFinished(qint64 size);
+
+private slots:
+    void getCalcResult(int exitCode, QProcess::ExitStatus);
+
+private:
+    QProcess * m_process;
+
+    qint64 m_size = 0; // 备份大小，单位字节
+};
+
+#endif // CALCBACKUPSIZE_H
diff --git a/backup-daemon/systembackupproxy.cpp b/backup-daemon/systembackupproxy.cpp
index f0876ed..93033bb 100644
--- a/backup-daemon/systembackupproxy.cpp
+++ b/backup-daemon/systembackupproxy.cpp
@@ -5,6 +5,7 @@
 #include "../common/mydusizetool.h"
 #include "mymountproxy.h"
 #include "parsebackuplist.h"
+#include "myprocess/calcbackupsize.h"
 
 IMPLEMENT_DYNCREATE(SystemBackupProxy)
 
@@ -29,11 +30,10 @@ void SystemBackupProxy::checkEnvEx()
     }
 
     // 2、检测备份是否增量备份
-    bool bInc = checkIsIncBackup();
-    m_backupWrapper.m_bIncrement = bInc;
+    checkIsIncBackup();
 
     // 3、检测空间是否满足备份
-    checkFreeCapacity(bInc);
+    checkFreeCapacity();
 
     qDebug() << "SystemBackupProxy::checkEnv invoke end";
 }
@@ -51,11 +51,12 @@ void SystemBackupProxy::cancelEx()
 bool SystemBackupProxy::checkIsIncBackup()
 {
     QString backupPath;
+    ParseBackupList::BackupPoint point;
     if (m_backupWrapper.m_uuid.isEmpty()) {
         QString xmlPath(Utils::getSysRootPath() + BACKUP_XML_PATH);
         xmlPath.replace("//", "/");
         ParseBackupList parser(xmlPath);
-        ParseBackupList::BackupPoint point = parser.getLastSysBackupPoint();
+        point = parser.getLastSysBackupPoint();
         if (point.m_uuid.isEmpty())
             return false;
         backupPath = Utils::getSysRootPath() + BACKUP_SNAPSHOTS_PATH + "/" + point.m_uuid + "/data";
@@ -64,30 +65,70 @@ bool SystemBackupProxy::checkIsIncBackup()
     }
 
     backupPath.replace("//", "/");
-    return Utils::isDirExist(backupPath);
+    if (Utils::isDirExist(backupPath)) {
+        m_backupWrapper.m_baseUuid = point.m_uuid;
+        m_backupWrapper.m_bIncrement = true;
+        return true;
+    }
+    return false;
 }
 
 /**
  * @brief 校验剩余空间是否满足备份
- * @param bInc，是否增量备份
- * @note 增量备份和全量备份计算空间方法不同
  */
-void SystemBackupProxy::checkFreeCapacity(bool bInc)
+void SystemBackupProxy::checkFreeCapacity()
 {
     // 1、计算待备份数据的大小
-    MyDuSizeTool du;
-    qint64 itotalSize = du.Do(m_backupWrapper.m_backupPaths, m_backupWrapper.m_backupExcludePaths, true);
-    if (-1 == itotalSize) {
-        qCritical() << "du system backup failed";
-        emit checkResult(int(BackupResult::DU_ERR));
-        return ;
-    }
+    qint64 itotalSize = calcSizeForBackup();
+    // 备份过程中会有一些临时文件产生，会占用一部分空间，故我们预留500M的空间
+    itotalSize += 500 * MB;
 
     // 2、计算备份分区剩余空间大小
     QString backupPath(Utils::getSysRootPath() + BACKUP_PATH);
     backupPath.replace("//", "/");
     QStorageInfo backupDisk(backupPath);
     qint64 freeSize = backupDisk.bytesFree();
+
+    // 3、校验空间是否足够
+    if (itotalSize > freeSize) {
+        emit checkResult(int(BackupResult::BACKUP_CAPACITY_IS_NOT_ENOUGH));
+        return ;
+    }
+}
+
+/**
+ * @brief 计算备份所需空间大小
+ * @return 计算备份所需空间大小,单位字节
+ */
+qint64 SystemBackupProxy::calcSizeForBackup()
+{
+    QStringList args;
+    if (m_backupWrapper.m_bIncrement) {
+        if (m_backupWrapper.m_uuid.isEmpty()) {
+            // 新增增量备份点场景
+            args = getRsyncArgs(SystemBackupScene::TRY_INC_SYSTEM_BACKUP);
+        } else {
+            // 在原来的备份点上增量备份场景
+            args = getRsyncArgs(SystemBackupScene::TRY_INC_SYSTEM_BACKUP_AT_BASE);
+        }
+    } else {
+        // 全量备份场景
+        args = getRsyncArgs(SystemBackupScene::TRY_SYSTEM_BACKUP);
+    }
+
+    // 拼接备份源路径和目标路径
+    QString srcPath = Utils::getSysRootPath();
+    srcPath += "/";
+    srcPath.replace("//", "/");
+    args << srcPath;
+    QString destPath = Utils::getSysRootPath();
+    destPath += CHECK_PATH;
+    destPath.replace("//", "/");
+    args << destPath;
+    Utils::mkpath(destPath);
+
+    CalcBackupSize calcator;
+    return calcator.calcBackupSize(args);
 }
 
 /**
@@ -103,22 +144,44 @@ QStringList SystemBackupProxy::getRsyncArgs(SystemBackupScene scene)
     case SystemBackupScene::SYSTEM_BACKUP :
         args << "-avAXW";
         args << "--progress";
+        args << "--ignore-missing-args";
         break ;
     case SystemBackupScene::INC_SYSTEM_BACKUP :
         args << "-avAXr";
         args << "--progress";
-        args << "--link-dest";
+        args << "--ignore-missing-args";
+        args << QString("--link-dest=../%1/data").arg(m_baseUuid);
+        break ;
+    case SystemBackupScene::INC_SYSTEM_BACKUP_AT_BASE :
+        args << "-avAXr";
+        args << "--progress";
+        args << "--ignore-missing-args";
+        args << "--delete";
         break ;
     case SystemBackupScene::TRY_SYSTEM_BACKUP :
-        args << "-avAXWn";
+        args << "-aAXWn";
         args << "--stats";
+        args << "--ignore-missing-args";
         break ;
     case SystemBackupScene::TRY_INC_SYSTEM_BACKUP :
-        args << "-avAXrn";
+        args << "-aAXrn";
         args << "--stats";
-        args << "--link-dest";
+        args << "--ignore-missing-args";
+        args << QString("--link-dest=../%1/data").arg(m_baseUuid);
+        break ;
+    case SystemBackupScene::TRY_INC_SYSTEM_BACKUP_AT_BASE :
+        args << "-aAXrn";
+        args << "--stats";
+        args << "--ignore-missing-args";
+        args << "--delete";
         break ;
     default:
+        return args;
+    }
+
+    // --exclude=排除路径设置
+    for (const QString & item : m_backupWrapper.m_backupExcludePaths) {
+        args << QString("--exclude=%1").arg(item);
     }
 
     return args;
diff --git a/backup-daemon/systembackupproxy.h b/backup-daemon/systembackupproxy.h
index 23d67d0..540c385 100644
--- a/backup-daemon/systembackupproxy.h
+++ b/backup-daemon/systembackupproxy.h
@@ -12,8 +12,10 @@ public:
     enum SystemBackupScene {
         SYSTEM_BACKUP,  // 系统备份
         INC_SYSTEM_BACKUP,  // 增量系统备份
+        INC_SYSTEM_BACKUP_AT_BASE, // 在原备份点里增量备份
         TRY_SYSTEM_BACKUP,  // 测试系统备份，可用于计算备份传输数据大小
         TRY_INC_SYSTEM_BACKUP, // 测试增量系统备份，可用于计算备份传输数据大小
+        TRY_INC_SYSTEM_BACKUP_AT_BASE, // 测试增量系统备份，在原备份点里增量备份，可用于计算备份传输数据大小
     };
 
     explicit SystemBackupProxy();
@@ -34,17 +36,22 @@ private:
     bool checkIsIncBackup();
 
     // 校验剩余空间是否满足备份
-    void checkFreeCapacity(bool bInc);
+    void checkFreeCapacity();
+
+    // 计算备份所需空间大小
+    qint64 calcSizeForBackup();
 
     /**
      * @brief 根据场景获取rsync命令参数
      * @param scene，场景
      * @return 组装好的rsync的参数信息
      */
-    QString getRsyncArgs(SystemBackupScene scene);
+    QStringList getRsyncArgs(SystemBackupScene scene);
 
     // 是否增量备份
     bool m_bIncrement = false;
+    // 基准备份点，新增增量备份点时用
+    QString m_baseUuid;
 };
 
 #endif // SYSTEMBACKUPPROXY_H
diff --git a/common/mydefine.h b/common/mydefine.h
index 32cef9c..62eac61 100644
--- a/common/mydefine.h
+++ b/common/mydefine.h
@@ -12,6 +12,7 @@
 #define BACKUP_SNAPSHOTS_PATH "/backup/snapshots"
 #define BACKUP_XML_PATH "/backup/snapshots/backuplist.xml"
 #define EXCLUDE_FILE_PATH "/backup/snapshots/.exclude"
+#define CHECK_PATH "/backup/snapshots/check/data/"
 
 #define BOOTINFO_PATH "/etc/.bootinfo"
 #define FSTAB_PATH "/etc/fstab"
@@ -82,6 +83,8 @@ struct BackupWrapper {
     int m_gid = -1;
     // 是否增量备份
     bool m_bIncrement = false;
+    // 新增备份点时增量备份的基准uuid
+    QString m_baseUuid;
 
     static void registerMetaType();
 };
diff --git a/common/mydusizetool.cpp b/common/mydusizetool.cpp
index 629cdc1..693b1ca 100644
--- a/common/mydusizetool.cpp
+++ b/common/mydusizetool.cpp
@@ -51,12 +51,12 @@ qint64 MyDuSizeTool::_Do(QStringList paths, QStringList excludePaths, bool needE
     }
 
     QString cmd = "du";
-    for (QString& x : paths) {
+    for (const QString& x : paths) {
         cmd.append(QString(" \"%1\"").arg(x));
     }
     if (needExclude) {
-        for (QString& item : excludePaths) {
-            QString arg = QString(" --exclude=\"%1\"").arg(x);
+        for (const QString& item : excludePaths) {
+            QString arg = QString(" --exclude=\"%1\"").arg(item);
             cmd.append(arg);
         }
     }
diff --git a/common/utils.cpp b/common/utils.cpp
index 7e4e0e2..d03ca76 100644
--- a/common/utils.cpp
+++ b/common/utils.cpp
@@ -287,6 +287,7 @@ bool Utils::generateExcludePathsFile()
     in << "/swap_file" << endl;
     in << "/sys" << endl; //添加*(/sys/*)，表示如果/sys目录不存在，则会拷贝/sys，但不会拷贝/sys下的内容
     in << "/tmp" << endl;
+    in << "/var/lib/docker/overlay2" << endl;
     // 安卓兼容的这个里面很多文件都是设置了特殊扩展文件属性，lsetxattr无法设置成功，听取安卓兼容模块同事的意见不用管这个文件夹，其实是从home下挂载的
     in << "/var/lib/kmre" << endl;
     in << "/var/lib/udisks2" << endl;
@@ -343,6 +344,7 @@ QStringList Utils::getFromExcludePathsFile()
         list << "/swap_file";
         list << "/sys";
         list << "/tmp";
+        list << "/var/lib/docker/overlay2";
         list << "/var/lib/kmre";
         list << "/var/lib/udisks2";
         list << "/var/log";