diff --git a/deps/oblib/src/lib/charset/ob_charset.cpp b/deps/oblib/src/lib/charset/ob_charset.cpp
index 9ea14b08e8a814381930f0e9931c948aca865fa2..6bd8b6f7b018db64656eeb7741607664816575d2 100644
--- a/deps/oblib/src/lib/charset/ob_charset.cpp
+++ b/deps/oblib/src/lib/charset/ob_charset.cpp
@@ -2235,7 +2235,9 @@ int ObCharset::charset_convert(ObIAllocator& alloc, const ObString& in, const Ob
     ret = OB_INVALID_ARGUMENT;
     LOG_WARN("invalid collation type", K(ret), K(src_cs_type), K(dst_cs_type));
   } else {
-    if (0 == in.length() || charset_type_by_coll(src_cs_type) == charset_type_by_coll(dst_cs_type)) {
+    if (0 == in.length()
+        || charset_type_by_coll(src_cs_type) == charset_type_by_coll(dst_cs_type)
+        || charset_type_by_coll(dst_cs_type) == CHARSET_BINARY) {
       if (!(convert_flag & COPY_STRING_ON_SAME_CHARSET)) {
         out = in;
       } else {
@@ -2243,6 +2245,24 @@ int ObCharset::charset_convert(ObIAllocator& alloc, const ObString& in, const Ob
           LOG_WARN("fail to write string", K(ret), K(in));
         }
       }
+    } else if (charset_type_by_coll(src_cs_type) == CHARSET_BINARY) {
+      char *buf = nullptr;
+      int32_t align_offset = 0;
+      int32_t res_buf_len = 0;
+      int mbminlen = ObCharset::get_charset(dst_cs_type)->mbminlen;
+      if (mbminlen > 0 && in.length() % mbminlen != 0) {
+        align_offset = mbminlen - in.length() % mbminlen;
+      }
+      res_buf_len = in.length() + align_offset;
+      if (OB_ISNULL(buf = static_cast<char*>(alloc.alloc(res_buf_len)))) {
+        ret = OB_ALLOCATE_MEMORY_FAILED;
+        out.reset();
+        LOG_WARN("allocate memory failed", K(ret), K(in), K(align_offset));
+      } else {
+        MEMCPY(buf + align_offset, in.ptr(), in.length());
+        MEMSET(buf, 0, align_offset);
+        out.assign_ptr(buf, res_buf_len);
+      }
     } else {
       const uint32_t res_buf_len = in.length() * 4;
       uint32_t res_len = 0;
diff --git a/src/sql/ob_sql_utils.cpp b/src/sql/ob_sql_utils.cpp
index 40586bb2df5760fa4039070f9b8910f9332d7eb7..a27c1e37aed8ad8dc20b4ddb77d99b46f71530d1 100644
--- a/src/sql/ob_sql_utils.cpp
+++ b/src/sql/ob_sql_utils.cpp
@@ -2886,32 +2886,8 @@ int ObSQLUtils::clear_evaluated_flag(const ObExprPtrIArray& calc_exprs, ObEvalCt
 int ObSQLUtils::copy_and_convert_string_charset(
     ObIAllocator& allocator, const ObString& src, ObString& dst, ObCollationType src_coll, ObCollationType dst_coll)
 {
-  int ret = OB_SUCCESS;
-
-  if (OB_UNLIKELY(!ObCharset::is_valid_collation(src_coll) || !ObCharset::is_valid_collation(dst_coll))) {
-    ret = OB_INVALID_ARGUMENT;
-    LOG_WARN("invalid input collation", K(ret), K(src_coll), K(dst_coll));
-  } else if (OB_ISNULL(src.ptr()) || OB_UNLIKELY(0 >= src.length())) {
-    dst.reset();
-  } else if (ObCharset::charset_type_by_coll(src_coll) == ObCharset::charset_type_by_coll(dst_coll)) {
-    OZ(ob_write_string(allocator, src, dst));
-  } else {
-    const int32_t CharConvertFactorNum = 4;
-    char* buf = nullptr;
-    int32_t buf_len = src.length() * CharConvertFactorNum;
-    uint32_t result_len = 0;
-    if (OB_ISNULL(buf = static_cast<char*>(allocator.alloc(buf_len)))) {
-      ret = OB_ALLOCATE_MEMORY_FAILED;
-      LOG_WARN("allocate memory failed", K(ret), "len", buf_len);
-    } else if (OB_FAIL(
-                   ObCharset::charset_convert(src_coll, src.ptr(), src.length(), dst_coll, buf, buf_len, result_len))) {
-      LOG_WARN("fail to do charset convert", K(ret));
-    } else {
-      dst.assign_ptr(buf, result_len);
-    }
-  }
-
-  return ret;
+  return ObCharset::charset_convert(allocator, src, src_coll, dst_coll, dst,
+                                    ObCharset::COPY_STRING_ON_SAME_CHARSET);
 }
 
 int ObSQLUtils::update_session_last_schema_version(