问wa万象优图OCR身份证识别接口返回400？

按照demo，请求数据如下，但是返回400，求解。。。。：

POST /ocr/idcard HTTP/1.1

Content-Type:multipart/form-data;boundary=-------------------------acebdf13572468

Authorization:****************************************************************

Host: service.image.myqcloud.com

Content-Length: 500

---------------------------acebdf13572468

Content-Disposition: form-data; name="appid";

1254234995

---------------------------acebdf13572468

Content-Disposition: form-data; name="bucket";

orctest

---------------------------acebdf13572468

Content-Disposition: form-data; name="card_type";

0

---------------------------acebdf13572468

Content-Disposition: form-data; name="image[0]"; filename="1262041524.jpg"

Content-Type: image/jpeg

---------------------------acebdf13572468--