diff --git a/src/client/src/tscSQLParser.c b/src/client/src/tscSQLParser.c
index 2566e171f4..08c0e7e6d0 100644
--- a/src/client/src/tscSQLParser.c
+++ b/src/client/src/tscSQLParser.c
@@ -2642,7 +2642,7 @@ static int32_t doExtractColumnFilterInfo(SQueryInfo* pQueryInfo, SColumnFilterIn
 
       tVariantDump(&pRight->val, (char*)pColumnFilter->pz, colType, false);
 
-      size_t len = wcslen((wchar_t*)pColumnFilter->pz);
+      size_t len = twcslen((wchar_t*)pColumnFilter->pz);
       pColumnFilter->len = len * TSDB_NCHAR_SIZE;
     } else {
       tVariantDump(&pRight->val, (char*)&pColumnFilter->lowerBndd, colType, false);
diff --git a/src/query/src/tvariant.c b/src/query/src/tvariant.c
index 1650db6cfd..1b64a7aefa 100644
--- a/src/query/src/tvariant.c
+++ b/src/query/src/tvariant.c
@@ -184,7 +184,7 @@ int32_t tVariantToString(tVariant *pVar, char *dst) {
     
     case TSDB_DATA_TYPE_NCHAR: {
       dst[0] = '\'';
-      taosUcs4ToMbs(pVar->wpz, (wcslen(pVar->wpz) + 1) * TSDB_NCHAR_SIZE, dst + 1);
+      taosUcs4ToMbs(pVar->wpz, (twcslen(pVar->wpz) + 1) * TSDB_NCHAR_SIZE, dst + 1);
       int32_t len = strlen(dst);
       dst[len] = '\'';
       dst[len + 1] = 0;
@@ -416,7 +416,7 @@ static int32_t toNchar(tVariant *pVariant, char **pDest, int32_t *pDestSize) {
     }
     
     pVariant->wpz = pWStr;
-    *pDestSize = wcslen(pVariant->wpz);
+    *pDestSize = twcslen(pVariant->wpz);
     
     // shrink the allocate memory, no need to check here.
     char* tmp = realloc(pVariant->wpz, (*pDestSize + 1)*TSDB_NCHAR_SIZE);
diff --git a/src/query/tests/unitTest.cpp b/src/query/tests/unitTest.cpp
index c5b1cbf858..59fd326ef4 100644
--- a/src/query/tests/unitTest.cpp
+++ b/src/query/tests/unitTest.cpp
@@ -66,7 +66,7 @@ static void _init_tvariant_nchar(tVariant* t) {
   t->wpz = (wchar_t*)calloc(1, 20 * TSDB_NCHAR_SIZE);
   t->nType = TSDB_DATA_TYPE_NCHAR;
   wcscpy(t->wpz, L"-2000000.8765");
-  t->nLen = wcslen(t->wpz);
+  t->nLen = twcslen(t->wpz);
 }
 
 int main(int argc, char** argv) {
diff --git a/src/util/inc/tutil.h b/src/util/inc/tutil.h
index e3e52d46ff..a314f0e31d 100644
--- a/src/util/inc/tutil.h
+++ b/src/util/inc/tutil.h
@@ -119,6 +119,8 @@ extern "C" {
 
 uint32_t taosRand(void);
 
+size_t twcslen(const wchar_t *wcs);
+
 int32_t strdequote(char *src);
 
 size_t strtrim(char *src);
diff --git a/src/util/src/tutil.c b/src/util/src/tutil.c
index 150767643f..f8fca7392c 100644
--- a/src/util/src/tutil.c
+++ b/src/util/src/tutil.c
@@ -57,6 +57,23 @@ uint32_t taosRand(void)
 }
 #endif
 
+size_t twcslen(const wchar_t *wcs) {
+  int *wstr = (int *)wcs;
+  if (NULL == wstr) {
+    return 0;
+  }
+
+  size_t n = 0;
+  while (1) {
+    if (0 == *wstr++) {
+      break;
+    }
+    n++;
+  }
+
+  return n;
+}
+
 int32_t strdequote(char *z) {
   if (z == NULL) {
     return 0;