diff --git a/session.go b/session.go
index af75451..5e4da77 100644
--- a/session.go
+++ b/session.go
@@ -43,26 +43,16 @@ func (body *Body) IOBody() interface{} {
 
 // ContentType 获取ContentType
 func (body *Body) ContentType() string {
-	content := body.prefix + ";"
+	content := body.prefix
 	for kvalue := range body.contentTypes {
 		content += kvalue + ";"
 	}
 	return strings.TrimRight(content, ";")
 }
 
-// AddPrefix AddPrefix 和 AddContentType的顺序会影响到ContentType()的返回结果
-func (body *Body) AddPrefix(ct string) {
-	content := body.prefix
-	for _, v := range strings.Split(ct, ";") {
-		v = strings.Trim(v, " ")
-		if v != "" {
-			if body.prefix != v {
-				content += v + ";"
-			}
-		}
-	}
-	content = strings.TrimRight(content, ";")
-	body.prefix = content
+// SetPrefix SetPrefix 和 AddContentType的顺序会影响到ContentType()的返回结果
+func (body *Body) SetPrefix(ct string) {
+	body.prefix = strings.TrimRight(ct, ";") + ";"
 }
 
 // AddContentType 添加 Add Type类型
@@ -90,7 +80,7 @@ type IBody interface {
 	// AppendContent
 	AddContentType(ct string)
 	// AddPrefix 添加 Prefix
-	AddPrefix(ct string)
+	SetPrefix(ct string)
 }
 
 // BasicAuth 帐号认真结构
diff --git a/workflow.go b/workflow.go
index bf3235a..1e11136 100644
--- a/workflow.go
+++ b/workflow.go
@@ -1,7 +1,6 @@
 package requests
 
 import (
-	"log"
 	"net/http"
 	"net/url"
 	"regexp"
@@ -184,9 +183,9 @@ func (wf *Workflow) SetBody(params ...interface{}) *Workflow {
 		if plen >= 2 {
 			t := params[plen-1]
 			defaultContentType = t.(string)
-			wf.Body.AddPrefix(defaultContentType)
+			wf.Body.SetPrefix(defaultContentType)
 		} else {
-			wf.Body.AddPrefix(defaultContentType)
+			wf.Body.SetPrefix(defaultContentType)
 		}
 
 		if defaultContentType == TypeFormData {
@@ -211,7 +210,6 @@ func (wf *Workflow) SetBody(params ...interface{}) *Workflow {
 
 		}
 	}
-	log.Println(wf.Body.ContentType())
 	return wf
 }