diff --git a/source/dnode/mgmt/mgmt_mnode/src/mmFile.c b/source/dnode/mgmt/mgmt_mnode/src/mmFile.c
index f736ffd0c8ec4f4a4517f50080ecdac7f06c922d..ff459353f45c3f242f45bc53fb100b0560a046ad 100644
--- a/source/dnode/mgmt/mgmt_mnode/src/mmFile.c
+++ b/source/dnode/mgmt/mgmt_mnode/src/mmFile.c
@@ -15,6 +15,7 @@
 
 #define _DEFAULT_SOURCE
 #include "mmInt.h"
+#include "tjson.h"
 
 int32_t mmReadFile(const char *path, SMnodeOpt *pOption) {
   int32_t   code = TSDB_CODE_INVALID_JSON_FORMAT;
@@ -130,56 +131,69 @@ _OVER:
   return code;
 }
 
-int32_t mmWriteFile(const char *path, const SMnodeOpt *pOption) {
-  char file[PATH_MAX] = {0};
-  char realfile[PATH_MAX] = {0};
-  snprintf(file, sizeof(file), "%s%smnode.json.bak", path, TD_DIRSEP);
-  snprintf(realfile, sizeof(realfile), "%s%smnode.json", path, TD_DIRSEP);
-
-  TdFilePtr pFile = taosOpenFile(file, TD_FILE_CREATE | TD_FILE_WRITE | TD_FILE_TRUNC);
-  if (pFile == NULL) {
-    terrno = TAOS_SYSTEM_ERROR(errno);
-    dError("failed to write %s since %s", file, terrstr());
-    return -1;
-  }
-
-  int32_t len = 0;
-  int32_t maxLen = 4096;
-  char   *content = taosMemoryCalloc(1, maxLen + 1);
-
-  len += snprintf(content + len, maxLen - len, "{\n");
+static int32_t mmEncodeOption(SJson *pJson, const SMnodeOpt *pOption) {
   if (pOption->deploy && pOption->numOfReplicas > 0) {
-    len += snprintf(content + len, maxLen - len, "  \"selfIndex\": %d,\n", pOption->selfIndex);
-    len += snprintf(content + len, maxLen - len, "  \"replicas\": [{\n");
+    if (tjsonAddDoubleToObject(pJson, "selfIndex", pOption->selfIndex) < 0) return -1;
+
+    SJson *replicas = tjsonCreateArray();
+    if (replicas == NULL) return -1;
+    if (tjsonAddItemToObject(pJson, "replicas", replicas) < 0) return -1;
 
     for (int32_t i = 0; i < pOption->numOfReplicas; ++i) {
+      SJson *replica = tjsonCreateObject();
+      if (replica == NULL) return -1;
+
       const SReplica *pReplica = pOption->replicas + i;
-      if (pReplica != NULL && pReplica->id > 0) {
-        len += snprintf(content + len, maxLen - len, "    \"id\": %d,\n", pReplica->id);
-        len += snprintf(content + len, maxLen - len, "    \"fqdn\": \"%s\",\n", pReplica->fqdn);
-        len += snprintf(content + len, maxLen - len, "    \"port\": %u\n", pReplica->port);
-      }
-      if (i < pOption->numOfReplicas - 1) {
-        len += snprintf(content + len, maxLen - len, "  },{\n");
-      } else {
-        len += snprintf(content + len, maxLen - len, "  }],\n");
-      }
+      if (tjsonAddDoubleToObject(replica, "id", pReplica->id) < 0) return -1;
+      if (tjsonAddStringToObject(replica, "fqdn", pReplica->fqdn) < 0) return -1;
+      if (tjsonAddDoubleToObject(replica, "port", pReplica->port) < 0) return -1;
+      if (tjsonAddItemToArray(replicas, replica) < 0) return -1;
     }
   }
-  len += snprintf(content + len, maxLen - len, "  \"deployed\": %d\n", pOption->deploy);
-  len += snprintf(content + len, maxLen - len, "}\n");
 
-  taosWriteFile(pFile, content, len);
-  taosFsyncFile(pFile);
+  if (tjsonAddDoubleToObject(pJson, "deployed", pOption->deploy) < 0) return -1;
+
+  return 0;
+}
+
+int32_t mmWriteFile(const char *path, const SMnodeOpt *pOption) {
+  int32_t   code = -1;
+  char     *buffer = NULL;
+  SJson    *pJson = NULL;
+  TdFilePtr pFile = NULL;
+  char      file[PATH_MAX] = {0};
+  char      realfile[PATH_MAX] = {0};
+  snprintf(file, sizeof(file), "%s%smnode.json.bak", path, TD_DIRSEP);
+  snprintf(realfile, sizeof(realfile), "%s%smnode.json", path, TD_DIRSEP);
+
+  pFile = taosOpenFile(file, TD_FILE_CREATE | TD_FILE_WRITE | TD_FILE_TRUNC);
+  if (pFile == NULL) goto _OVER;
+
+  terrno = TSDB_CODE_OUT_OF_MEMORY;
+  pJson = tjsonCreateObject();
+  if (pJson == NULL) goto _OVER;
+  if (mmEncodeOption(pJson, pOption) != 0) goto _OVER;
+
+  buffer = tjsonToString(pJson);
+  if (buffer == NULL) goto _OVER;
+
+  int32_t len = strlen(buffer);
+  if (taosWriteFile(pFile, buffer, len) <= 0) goto _OVER;
+  if (taosFsyncFile(pFile) < 0) goto _OVER;
   taosCloseFile(&pFile);
-  taosMemoryFree(content);
 
-  if (taosRenameFile(file, realfile) != 0) {
-    terrno = TAOS_SYSTEM_ERROR(errno);
-    dError("failed to rename %s since %s", file, terrstr());
-    return -1;
-  }
+  if (taosRenameFile(file, realfile) != 0) goto _OVER;
 
-  dDebug("succeed to write %s, deployed:%d", realfile, pOption->deploy);
-  return 0;
+  code = 0;
+  dInfo("succeed to write mnode file:%s, deloyed:%d", realfile, pOption->deploy);
+
+_OVER:
+  if (pJson != NULL) tjsonDelete(pJson);
+  if (buffer != NULL) taosMemoryFree(buffer);
+  if (pFile != NULL) taosCloseFile(&pFile);
+
+  if (code != 0) {
+    dError("failed to write mnode file:%s since %s, deloyed:%d", realfile, terrstr(), pOption->deploy);
+  }
+  return code;
 }