diff --git a/src/obproxy/proxy/mysqllib/ob_2_0_protocol_utils.cpp b/src/obproxy/proxy/mysqllib/ob_2_0_protocol_utils.cpp
index 8f8dd07f3be1546b44888158597abb21c1994666..64be6deab5771e8fd969f251409cc8aea44f505e 100644
--- a/src/obproxy/proxy/mysqllib/ob_2_0_protocol_utils.cpp
+++ b/src/obproxy/proxy/mysqllib/ob_2_0_protocol_utils.cpp
@@ -118,8 +118,8 @@ int ObProto20Utils::analyze_one_compressed_packet(
     int64_t block_len = reader.block_read_avail();
     char *buf_start = reader.start();
 
+    char mysql_hdr[MYSQL_COMPRESSED_OB20_HEALDER_LENGTH];
     if (OB_UNLIKELY(block_len < MYSQL_COMPRESSED_OB20_HEALDER_LENGTH)) {
-      char mysql_hdr[MYSQL_COMPRESSED_OB20_HEALDER_LENGTH];
       char *written_pos = reader.copy(mysql_hdr, MYSQL_COMPRESSED_OB20_HEALDER_LENGTH, 0);
       if (OB_UNLIKELY(written_pos != mysql_hdr + MYSQL_COMPRESSED_OB20_HEALDER_LENGTH)) {
         ret = OB_ERR_UNEXPECTED;
diff --git a/src/obproxy/proxy/mysqllib/ob_mysql_analyzer_utils.cpp b/src/obproxy/proxy/mysqllib/ob_mysql_analyzer_utils.cpp
index 0502af7ef7b60adec10a92308bd9275ac1f86606..8653f70ef03966d07ac5934cd0ca6d4799caee70 100644
--- a/src/obproxy/proxy/mysqllib/ob_mysql_analyzer_utils.cpp
+++ b/src/obproxy/proxy/mysqllib/ob_mysql_analyzer_utils.cpp
@@ -41,8 +41,8 @@ int ObMysqlAnalyzerUtils::analyze_one_compressed_packet(
     int64_t block_len = reader.block_read_avail();
     char *buf_start = reader.start();
 
+    char mysql_hdr[MYSQL_COMPRESSED_HEALDER_LENGTH];
     if (OB_UNLIKELY(block_len < MYSQL_COMPRESSED_HEALDER_LENGTH)) {
-      char mysql_hdr[MYSQL_COMPRESSED_HEALDER_LENGTH];
       char *written_pos = reader.copy(mysql_hdr, MYSQL_COMPRESSED_HEALDER_LENGTH, 0);
       if (OB_UNLIKELY(written_pos != mysql_hdr + MYSQL_COMPRESSED_HEALDER_LENGTH)) {
         ret = OB_ERR_UNEXPECTED;
diff --git a/src/obproxy/stat/ob_stat_processor.cpp b/src/obproxy/stat/ob_stat_processor.cpp
index 87037aa8c89c3eef1e3bf4f01fc579aef111f1c7..da5da868334eeb58193dcc29a7b29c1efd55952e 100644
--- a/src/obproxy/stat/ob_stat_processor.cpp
+++ b/src/obproxy/stat/ob_stat_processor.cpp
@@ -359,7 +359,7 @@ int ObStatProcessor::register_raw_stat(
   ObRecData data_default;
   memset(&data_default, 0, sizeof(ObRecData));
 
-  if (OB_UNLIKELY(!check_argument(rsb, id)) || OB_UNLIKELY(sync_type > SYNC_MAX)) {
+  if (OB_UNLIKELY(!check_argument(rsb, id)) || OB_UNLIKELY(sync_type >= SYNC_MAX)) {
     ret = OB_INVALID_ARGUMENT;
     LOG_WARN("invalid rsb or id", K(rsb), K(id), K(sync_type), K(ret));
   } else {
diff --git a/src/obproxy/utils/ob_proxy_blowfish.cpp b/src/obproxy/utils/ob_proxy_blowfish.cpp
index 24a80018a7a3c0e81aae0704f64696f542579bd0..8c31ff787de2a90753ad3dea980f659007cf591b 100644
--- a/src/obproxy/utils/ob_proxy_blowfish.cpp
+++ b/src/obproxy/utils/ob_proxy_blowfish.cpp
@@ -184,9 +184,7 @@ int ObBlowFish::convert_large_str_to_hex(const char *str, const int64_t str_len,
       int tmp_value = 0;
       for(int64_t i = start_pos; out_idx >= padding_len; --out_idx) {
         if (4 == byte_pos) {
-          if (i < 0) {
-            tmp_value = 0;
-          } else if (i >= int_num) {
+          if (i >= int_num) {
             tmp_value = is_negative ? -1 : 0;
           } else {
             int32_t var2 = static_cast<int32_t>(mag[int_num - i - 1 + start_pos]);