diff --git a/webmagic-core/src/main/java/us/codecraft/webmagic/Request.java b/webmagic-core/src/main/java/us/codecraft/webmagic/Request.java
index 1978792..c8c5978 100644
--- a/webmagic-core/src/main/java/us/codecraft/webmagic/Request.java
+++ b/webmagic-core/src/main/java/us/codecraft/webmagic/Request.java
@@ -115,14 +115,18 @@ public class Request implements Serializable {
         return params;
     }
     /**
-     * POST/GET参数设置
+     * set params for request
+     * <br>
+     * DO NOT set this for request already has params, like 'https://github.com/search?q=webmagic'
      * @param params params
      * */
     public void setParams(Map<String, String> params) {
         this.params = params;
     }
     /**
-     * POST/GET参数设置
+     * set params for request
+     * <br>
+     * DO NOT set this for request already has params, like 'https://github.com/search?q=webmagic'
      * @param key key
      * @param value value
      * */
diff --git a/webmagic-core/src/main/java/us/codecraft/webmagic/downloader/HttpClientDownloader.java b/webmagic-core/src/main/java/us/codecraft/webmagic/downloader/HttpClientDownloader.java
index 26a7288..0c11149 100644
--- a/webmagic-core/src/main/java/us/codecraft/webmagic/downloader/HttpClientDownloader.java
+++ b/webmagic-core/src/main/java/us/codecraft/webmagic/downloader/HttpClientDownloader.java
@@ -162,13 +162,7 @@ public class HttpClientDownloader extends AbstractDownloader {
         String method = request.getMethod();
         if (method == null || method.equalsIgnoreCase(HttpConstant.Method.GET)) {
             //default get
-            RequestBuilder requestBuilder=RequestBuilder.get();
-            if (request.getParams() != null) {
-                for (Map.Entry<String, String> entry : request.getParams().entrySet()) {
-                    requestBuilder.addParameter(entry.getKey(), entry.getValue());
-                }
-            }
-            return requestBuilder;
+            return addParams(RequestBuilder.get(),request.getParams());
         } else if (method.equalsIgnoreCase(HttpConstant.Method.POST)) {
             RequestBuilder requestBuilder = RequestBuilder.post();
             NameValuePair[] nameValuePair = (NameValuePair[]) request.getExtra("nameValuePair");
@@ -184,17 +178,26 @@ public class HttpClientDownloader extends AbstractDownloader {
             requestBuilder.setEntity(new UrlEncodedFormEntity(allNameValuePair, Charset.forName("utf8")));
             return requestBuilder;
         } else if (method.equalsIgnoreCase(HttpConstant.Method.HEAD)) {
-            return RequestBuilder.head();
+            return addParams(RequestBuilder.head(),request.getParams());
         } else if (method.equalsIgnoreCase(HttpConstant.Method.PUT)) {
-            return RequestBuilder.put();
+            return addParams(RequestBuilder.put(),request.getParams());
         } else if (method.equalsIgnoreCase(HttpConstant.Method.DELETE)) {
-            return RequestBuilder.delete();
+            return addParams(RequestBuilder.delete(),request.getParams());
         } else if (method.equalsIgnoreCase(HttpConstant.Method.TRACE)) {
-            return RequestBuilder.trace();
+            return addParams(RequestBuilder.trace(),request.getParams());
         }
         throw new IllegalArgumentException("Illegal HTTP Method " + method);
     }
 
+    private RequestBuilder addParams(RequestBuilder requestBuilder, Map<String, String> params) {
+        if (params != null) {
+            for (Map.Entry<String, String> entry : params.entrySet()) {
+                requestBuilder.addParameter(entry.getKey(), entry.getValue());
+            }
+        }
+        return requestBuilder;
+    }
+
     protected Page handleResponse(Request request, String charset, HttpResponse httpResponse, Task task) throws IOException {
         String content = getContent(charset, httpResponse);
         Page page = new Page();