diff --git a/base.go b/base.go
index cfe3e5d..ea243e9 100644
--- a/base.go
+++ b/base.go
@@ -19,10 +19,12 @@ func buildBodyRequest(wf *Workflow) *http.Request {
 		switch wf.Body.GetIOBody().(type) {
 		case []byte:
 			bodybuf = bytes.NewBuffer(wf.Body.GetIOBody().([]byte))
+		case string:
+			bodybuf = bytes.NewBuffer([]byte(wf.Body.GetIOBody().(string)))
 		case *bytes.Buffer:
 			bodybuf = bytes.NewBuffer(wf.Body.GetIOBody().(*bytes.Buffer).Bytes())
 		default:
-			panic(errors.New("the type is not exist, type is" + reflect.TypeOf(wf.Body.GetIOBody()).String()))
+			panic(errors.New("the type is not exist, type is " + reflect.TypeOf(wf.Body.GetIOBody()).String()))
 		}
 		req, err = http.NewRequest(wf.Method, wf.GetRawURL(), bodybuf)
 	}
diff --git a/session.go b/session.go
index 93126d6..a33c978 100644
--- a/session.go
+++ b/session.go
@@ -307,6 +307,13 @@ func (ses *Session) ClearCookies() {
 	ses.client.Jar = ses.cookiejar
 }
 
+// Head 请求
+func (ses *Session) Head(url string) *Workflow {
+	wf := NewWorkflow(ses, url)
+	wf.Method = "HEAD"
+	return wf
+}
+
 // Get 请求
 func (ses *Session) Get(url string) *Workflow {
 	wf := NewWorkflow(ses, url)
@@ -335,20 +342,6 @@ func (ses *Session) Patch(url string) *Workflow {
 	return wf
 }
 
-// Delete 请求
-func (ses *Session) Delete(url string) *Workflow {
-	wf := NewWorkflow(ses, url)
-	wf.Method = "DELETE"
-	return wf
-}
-
-// Head 请求
-func (ses *Session) Head(url string) *Workflow {
-	wf := NewWorkflow(ses, url)
-	wf.Method = "HEAD"
-	return wf
-}
-
 // Options 请求
 func (ses *Session) Options(url string) *Workflow {
 	wf := NewWorkflow(ses, url)
@@ -356,6 +349,13 @@ func (ses *Session) Options(url string) *Workflow {
 	return wf
 }
 
+// Delete 请求
+func (ses *Session) Delete(url string) *Workflow {
+	wf := NewWorkflow(ses, url)
+	wf.Method = "DELETE"
+	return wf
+}
+
 // CloseIdleConnections  closes the idle connections that a session client may make use of
 // 从levigross/grequests 借鉴
 func (ses *Session) CloseIdleConnections() {