diff --git a/index.js b/index.js
index 0c25d8f..c292ad2 100644
--- a/index.js
+++ b/index.js
@@ -118,11 +118,14 @@ module.exports = {
    * @param  {Str} encode [hex/base64]
    */
   md5(str, encode) {
-    if (typeof str !== 'string' && typeof str !== 'number') {
+    if (typeof str === 'number') {
+      str += ''
+    }
+    if (typeof str !== 'string' && !Buffer.isBuffer(str)) {
       return str
     }
 
-    return this.hash('md5', str + '', encode)
+    return this.hash('md5', str, encode)
   },
 
   /**
@@ -144,11 +147,14 @@ module.exports = {
    * @param  {Str} encode [hex/base64]
    */
   sha1(str, encode) {
-    if (typeof str !== 'string' && typeof str !== 'number') {
+    if (typeof str === 'number') {
+      str += ''
+    }
+    if (typeof str !== 'string' && !Buffer.isBuffer(str)) {
       return str
     }
 
-    return this.hash('sha1', str + '', encode)
+    return this.hash('sha1', str, encode)
   },
 
   /**
@@ -170,11 +176,14 @@ module.exports = {
    * @param  {Str} encoding [hex/base64]
    */
   sha256(str, encoding) {
-    if (typeof str !== 'string' && typeof str !== 'number') {
+    if (typeof str === 'number') {
+      str += ''
+    }
+    if (typeof str !== 'string' && !Buffer.isBuffer(str)) {
       return str
     }
 
-    return this.hash('sha256', str + '', encoding)
+    return this.hash('sha256', str, encoding)
   },
 
   /**
diff --git a/package.json b/package.json
index b82830d..d09fd31 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "crypto.js",
-  "version": "1.1.4",
+  "version": "1.1.5",
   "description": "原生crypto加密模块的二次封装,简化常用加密函数的使用",
   "keywords": [
     "md5",