diff --git a/options.go b/options.go
index b1d2ab0..e6f9c64 100644
--- a/options.go
+++ b/options.go
@@ -14,8 +14,8 @@ type clientOptions struct {
 
 func defaultOptions() clientOptions {
 	return clientOptions{
-		TimeOut: time.Second * 120, // 默认超时120
-		Logger:  defaultLogger{},
+		TimeOut:   time.Second * 120, // 默认超时120
+		Logger:    defaultLogger{},
 	}
 }
 
diff --git a/params.go b/params.go
index fa539d2..09162c6 100644
--- a/params.go
+++ b/params.go
@@ -89,7 +89,18 @@ func SetParamsFormFile(fieldName, fileName string, fileBytes []byte) Param {
  */
 func SetParamsHeaders(h map[string]interface{}) Param {
 	return func(param *ClientParams) {
-		param.Headers = h
+		for key, _ := range h {
+			param.Headers[key] = h[key]
+		}
+	}
+}
+
+/**
+ * 设置UserAgent
+ */
+func SetUserAgent(userAgent UserAgent) Param {
+	return func(param *ClientParams) {
+		param.Headers["User-Agent"] = string(userAgent)
 	}
 }
 
diff --git a/request.go b/request.go
index 4857601..5fd4c63 100644
--- a/request.go
+++ b/request.go
@@ -40,7 +40,7 @@ func (p *ClientParams) parseUrl() error {
 func (p *ClientParams) parseHeaders(r *http.Request) {
 	if p.Headers != nil {
 		if r.Header.Get("User-Agent") == "" {
-			r.Header.Add("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:87.0) Gecko/20100101 Firefox/87.0 Send By Golang")
+			r.Header.Add("User-Agent", string(UserAgentChrome))
 		}
 		for k, v := range p.Headers {
 			switch value := v.(type) {
@@ -52,6 +52,8 @@ func (p *ClientParams) parseHeaders(r *http.Request) {
 				}
 			case ContentType:
 				r.Header.Set(k, string(value))
+			case UserAgent:
+				r.Header.Set(k, string(value))
 			}
 		}
 	}