diff --git a/cli/src/main.c b/cli/src/main.c
index 671ec6b..cf2f47f 100644
--- a/cli/src/main.c
+++ b/cli/src/main.c
@@ -131,7 +131,7 @@ static bool CheckFileLegality(const char* filePath, const size_t filePathLen,
         Logger("realpath failed!", LEVEL_ERROR, SCREEN_YES);
         return false;
     }
-    if (strstr(resolvedPath, filePath) == NULL) { // 存在软链接
+    if (strcmp(resolvedPath, filePath) != 0) { // 存在软链接
         Logger("filePath has a soft link!", LEVEL_ERROR, SCREEN_YES);
         return false;
     }
diff --git a/cli/src/u_mount.c b/cli/src/u_mount.c
index d4c1ccb..db2bfcc 100644
--- a/cli/src/u_mount.c
+++ b/cli/src/u_mount.c
@@ -37,6 +37,14 @@ int Mount(const char *src, const char *dst)
                 return -1;
             }
     }
+    if (S_ISDIR(fileStat.st_mode) != 0) { // 目录则增加递归校验子集
+        if (!GetFileSubsetAndCheck(src, strlen(src))) {
+            char* str = FormatLogMessage("Check file subset failed: %s.", src);
+            Logger(str, LEVEL_ERROR, SCREEN_YES);
+            free(str);
+            return -1;
+        }
+    }
     ret = mount(src, dst, NULL, mountFlags, NULL);
     if (ret < 0) {
         Logger("failed to mount src.", LEVEL_ERROR, SCREEN_YES);
diff --git a/cli/src/utils.c b/cli/src/utils.c
index 67ddc9e..49dcdb7 100644
--- a/cli/src/utils.c
+++ b/cli/src/utils.c
@@ -242,9 +242,6 @@ bool CheckExternalFile(const char* filePath, const size_t filePathLen,
     if ((filePathLen > PATH_MAX) || (filePathLen <= 0)) { // 长度越界
         return ShowExceptionInfo("filePathLen out of bounds!");
     }
-    if (strstr(filePath, "..") != NULL) { // 存在".."
-        return ShowExceptionInfo("filePath has an illegal character!");
-    }
     for (size_t iLoop = 0; iLoop < filePathLen; iLoop++) {
         if (!IsValidChar(filePath[iLoop])) { // 非法字符
             return ShowExceptionInfo("filePath has an illegal character!");
@@ -254,8 +251,75 @@ bool CheckExternalFile(const char* filePath, const size_t filePathLen,
     if (realpath(filePath, resolvedPath) == NULL && errno != ENOENT) {
         return ShowExceptionInfo("realpath failed!");
     }
-    if (strstr(resolvedPath, filePath) == NULL) { // 存在软链接
+    if (strcmp(resolvedPath, filePath) != 0) { // 存在软链接
         return ShowExceptionInfo("filePath has a soft link!");
     }
     return CheckLegality(resolvedPath, strlen(resolvedPath), maxFileSzieMb, checkOwner);
 }
+
+static bool CheckFileSubset(const char* filePath, const size_t filePathLen,
+    const size_t maxFileSzieMb)
+{
+    const unsigned long long maxFileSzieB = maxFileSzieMb * 1024 * 1024;
+    int iLoop;
+    if ((filePathLen > PATH_MAX) || (filePathLen <= 0)) { // 长度越界
+        return ShowExceptionInfo("filePathLen out of bounds!");
+    }
+    for (iLoop = 0; iLoop < filePathLen; iLoop++) {
+        if (!IsValidChar(filePath[iLoop])) { // 非法字符
+            return ShowExceptionInfo("filePath has an illegal character!");
+        }
+    }
+    char resolvedPath[PATH_MAX] = {0};
+    if (realpath(filePath, resolvedPath) == NULL && errno != ENOENT) {
+        return ShowExceptionInfo("realpath failed!");
+    }
+    if (strcmp(resolvedPath, filePath) != 0) { // 存在软链接
+        return ShowExceptionInfo("filePath has a soft link!");
+    }
+    struct stat fileStat;
+    if (stat(filePath, &fileStat) != 0) {
+        return ShowExceptionInfo("filePath does not exist or is not a file!");
+    }
+    if (fileStat.st_size >= maxFileSzieB) { // 文件大小超限
+        return ShowExceptionInfo("fileSize out of bounds!");
+    }
+    return true;
+}
+ 
+bool GetFileSubsetAndCheck(const char *basePath, const size_t basePathLen)
+{
+    DIR *dir = NULL;
+    struct dirent *ptr = NULL;
+    char base[PATH_MAX] = {0};
+ 
+    if ((dir = opendir(basePath)) == NULL) {
+        return ShowExceptionInfo("Open dir error!");
+    }
+    while ((ptr = readdir(dir)) != NULL) {
+        if (strcmp(ptr->d_name, ".") == 0 || strcmp(ptr->d_name, "..") == 0) {
+            continue;
+        }
+        memset_s(base, PATH_MAX, 0, PATH_MAX);
+        if (strcpy_s(base, PATH_MAX, basePath) != 0) {
+            return ShowExceptionInfo("Strcpy failed!");
+        }
+        if (strcat_sp(base, PATH_MAX, "/") != 0 ||
+            strcat_sp(base, PATH_MAX, ptr->d_name) != 0) {
+            return ShowExceptionInfo("Strcat failed!");
+        }
+        if (ptr->d_type == DT_REG) { // 文件
+            const size_t maxFileSzieMb = 10; // max 10 MB
+            if (!CheckFileSubset(base, strlen(base), maxFileSzieMb)) {
+                return false;
+            }
+        } else if (ptr->d_type == DT_LNK) { // 软链接
+            return ShowExceptionInfo("FilePath has a soft link!");
+        } else if (ptr->d_type == DT_DIR) { // 目录
+            if (!GetFileSubsetAndCheck(base, strlen(base))) {
+                return false;
+            }
+        }
+    }
+    return true;
+}
\ No newline at end of file
diff --git a/cli/src/utils.h b/cli/src/utils.h
index 88e195b..e320446 100644
--- a/cli/src/utils.h
+++ b/cli/src/utils.h
@@ -25,5 +25,5 @@ int MakeMountPoints(const char *path, mode_t mode);
 bool IsValidChar(const char c);
 bool CheckExternalFile(const char* filePath, const size_t filePathLen,
     const size_t maxFileSzieMb, const bool checkOwner);
-
+bool GetFileSubsetAndCheck(const char *basePath, const size_t basePathLen);
 #endif
\ No newline at end of file
diff --git a/install/deb/src/main.c b/install/deb/src/main.c
index 7375f91..46359dd 100644
--- a/install/deb/src/main.c
+++ b/install/deb/src/main.c
@@ -331,7 +331,7 @@ static bool IsValidChar(const char c)
     if (isalnum(c) != 0) {
         return true;
     }
-    // ._-/~为合法字符
+
     if ((c == '.') || (c == '_') ||
         (c == '-') || (c == '/') || (c == '~')) {
         return true;
@@ -345,9 +345,6 @@ static bool CheckExternalFile(const char* filePath, const size_t filePathLen,
     if ((filePathLen > PATH_MAX) || (filePathLen <= 0)) { // 长度越界
         return ShowExceptionInfo("filePathLen out of bounds!");
     }
-    if (strstr(filePath, "..") != NULL) { // 存在".."
-        return ShowExceptionInfo("filePath has an illegal character!");
-    }
     for (size_t iLoop = 0; iLoop < filePathLen; iLoop++) {
         if (!IsValidChar(filePath[iLoop])) { // 非法字符
             return ShowExceptionInfo("filePath has an illegal character!");