diff --git a/CMakeLists_Headers.txt b/CMakeLists_Headers.txt
index e6581ebb..396efcc0 100644
--- a/CMakeLists_Headers.txt
+++ b/CMakeLists_Headers.txt
@@ -77,7 +77,6 @@ set(INCLUDE_HEADERS
 	src/util/LRUCache.h
 	src/util/StringUtil.h
 	src/util/URIParser.h
-	src/util/MD5Util.h
 	src/factory/WFConnection.h
 	src/factory/WFTask.h
 	src/factory/WFTask.inl
diff --git a/src/include/workflow/MD5Util.h b/src/include/workflow/MD5Util.h
deleted file mode 120000
index 8d8eb0df..00000000
--- a/src/include/workflow/MD5Util.h
+++ /dev/null
@@ -1 +0,0 @@
-../../util/MD5Util.h
\ No newline at end of file
diff --git a/src/util/CMakeLists.txt b/src/util/CMakeLists.txt
index 94b8bcd6..74d4f190 100644
--- a/src/util/CMakeLists.txt
+++ b/src/util/CMakeLists.txt
@@ -6,7 +6,6 @@ set(SRC
 	EncodeStream.cc
 	StringUtil.cc
 	URIParser.cc
-	MD5Util.cc
 )
 
 add_library(${PROJECT_NAME} OBJECT ${SRC})
diff --git a/src/util/MD5Util.cc b/src/util/MD5Util.cc
deleted file mode 100644
index 9deeb33a..00000000
--- a/src/util/MD5Util.cc
+++ /dev/null
@@ -1,95 +0,0 @@
-/*
-  Copyright (c) 2019 Sogou, Inc.
-
-  Licensed under the Apache License, Version 2.0 (the "License");
-  you may not use this file except in compliance with the License.
-  You may obtain a copy of the License at
-
-      http://www.apache.org/licenses/LICENSE-2.0
-
-  Unless required by applicable law or agreed to in writing, software
-  distributed under the License is distributed on an "AS IS" BASIS,
-  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-  See the License for the specific language governing permissions and
-  limitations under the License.
-
-  Authors: Wu Jiaxu (wujiaxu@sogou-inc.com)
-*/
-
-#include <openssl/md5.h>
-#include <string.h>
-#include <string>
-#include "MD5Util.h"
-
-static inline void __md5(const std::string& str, unsigned char *md)
-{
-	MD5_CTX ctx;
-	MD5_Init(&ctx);
-	MD5_Update(&ctx, str.c_str(), str.size());
-	MD5_Final(md, &ctx);
-}
-
-std::string MD5Util::md5_bin(const std::string& str)
-{
-	unsigned char md[16];
-
-	__md5(str, md);
-	return std::string((const char *)md, 16);
-}
-
-static inline char __hex_char(int v)
-{
-	return v < 10 ? '0' + v : 'a' + v - 10;
-}
-
-static inline void __plain_hex(char *s, int ch)
-{
-	*s = __hex_char(ch / 16);
-	*(s + 1) = __hex_char(ch % 16);
-}
-
-std::string MD5Util::md5_string_32(const std::string& str)
-{
-	unsigned char md[16];
-	char out[32];
-
-	__md5(str, md);
-	for (int i = 0; i < 16; i++)
-		__plain_hex(out + (i * 2), md[i]);
-
-	return std::string((const char *)out, 32);
-}
-
-std::string MD5Util::md5_string_16(const std::string& str)
-{
-	unsigned char md[16];
-	char out[16];
-
-	__md5(str, md);
-	for (int i = 0; i < 8; i++)
-		__plain_hex(out + (i * 2), md[i + 4]);
-
-	return std::string((const char *)out, 16);
-}
-
-std::pair<uint64_t, uint64_t> MD5Util::md5_integer_32(const std::string& str)
-{
-	unsigned char md[16];
-	std::pair<uint64_t, uint64_t> res;
-
-	__md5(str, md);
-	memcpy(&res.first, md, sizeof (uint64_t));
-	memcpy(&res.second, md + 8, sizeof (uint64_t));
-	return res;
-}
-
-uint64_t MD5Util::md5_integer_16(const std::string& str)
-{
-	unsigned char md[16];
-	uint64_t res;
-
-	__md5(str, md);
-	memcpy(&res, md + 4, sizeof (uint64_t));
-	return res;
-}
-
diff --git a/src/util/MD5Util.h b/src/util/MD5Util.h
deleted file mode 100644
index 5dc356a2..00000000
--- a/src/util/MD5Util.h
+++ /dev/null
@@ -1,49 +0,0 @@
-/*
-  Copyright (c) 2019 Sogou, Inc.
-
-  Licensed under the Apache License, Version 2.0 (the "License");
-  you may not use this file except in compliance with the License.
-  You may obtain a copy of the License at
-
-      http://www.apache.org/licenses/LICENSE-2.0
-
-  Unless required by applicable law or agreed to in writing, software
-  distributed under the License is distributed on an "AS IS" BASIS,
-  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-  See the License for the specific language governing permissions and
-  limitations under the License.
-
-  Authors: Wu Jiaxu (wujiaxu@sogou-inc.com)
-*/
-
-#ifndef _MD5UTIL_H_
-#define _MD5UTIL_H_
-
-#include <stdint.h>
-#include <string>
-#include <utility>
-
-/**
- * @file   MD5Util.h
- * @brief  MD5 toolbox
- */
-
-// static class
-class MD5Util
-{
-public:
-	//128 bit binary data
-	static std::string md5_bin(const std::string& str);
-	//128 bit hex string style, lower case
-	static std::string md5_string_32(const std::string& str);
-	//64  bit hex string style, lower case
-	static std::string md5_string_16(const std::string& str);
-
-	//128 bit integer style
-	static std::pair<uint64_t, uint64_t> md5_integer_32(const std::string& str);
-	//64  bit integer style
-	static uint64_t md5_integer_16(const std::string& str);
-};
-
-#endif
-