diff --git a/frameworks/resmgr_lite/src/utils/string_utils.cpp b/frameworks/resmgr_lite/src/utils/string_utils.cpp
index c62419a638322e00a7693b50de8be57081e5e18f..1bf6e8442ca8fb63b26ad22ed293bfc6fd6ab2f1 100644
--- a/frameworks/resmgr_lite/src/utils/string_utils.cpp
+++ b/frameworks/resmgr_lite/src/utils/string_utils.cpp
@@ -24,6 +24,7 @@
 namespace OHOS {
 namespace Global {
 namespace Resource {
+constexpr int32_t MAX_BUFFER_LEN = 1024;
 std::string FormatString(const char *fmt, ...)
 {
     std::string strResult;
@@ -40,15 +41,14 @@ std::string FormatString(const char *fmt, va_list args)
 {
     std::string strResult;
     if (fmt != nullptr) {
+        char buf[MAX_BUFFER_LEN] = {0};
         va_list tmpArgs;
         va_copy(tmpArgs, args);
-        size_t nLength = vsnprintf(nullptr, 0, fmt, tmpArgs); // compute buffer size
-        va_end(tmpArgs);
-        std::vector<char> vBuffer(nLength + 1, '\0');
-        int nWritten = vsnprintf_s(&vBuffer[0], nLength + 1, nLength, fmt, args);
+        int nWritten = vsnprintf_s(buf, sizeof(buf), sizeof(buf) - 1, fmt, tmpArgs);
         if (nWritten > 0) {
-            strResult = &vBuffer[0];
+            strResult.append(buf, nWritten);
         }
+        va_end(tmpArgs);
     }
     return strResult;
 }