Ta的回复 ：var base64= File.ReadAllBytes(@"F:\text\A1.Jpeg"); string strbaser64 = Convert.ToBase64String(base64); // 图片的base64编码 string host = "https://aip.baidubce.com/rest/2.0/ocr/v1/general?access_token=" + Token; Encoding encoding = Encoding.Default; String str = "image=" + HttpUtility.UrlEncode(strbaser64); byte[] buffer = encoding.GetBytes(str); using (var httpclient=new HttpClient()) { httpclient.DefaultRequestHeaders.Accept. Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/x-www-form-urlencoded")); var httpResponse= httpclient.PostAsync(host, new ByteArrayContent(buffer)).Result; var result= httpResponse.Content.ReadAsStringAsync().Result; return result; }