請求ajax報錯 返回readyState0

在postman上可以正常請求，換成ajax就報錯了，直接執(zhí)行error

var params = {
                userNameId: "cni23026672"
            }
$.ajax({
                type:"post",
                url:serviceUrl+getReleaseList+"?pageNum=" + pageNum + "&pageSize=10",
                async:true,
                contentType: "application/json; charset=utf-8",
                timeout: 10000,
                data: params,
                dataType: "json",
                success: function(data) {
                    console.log(JSON.stringify(data))
                },
                error: function(err) {
                    console.log(JSON.stringify(err))
                }
            });

返回錯誤信息：

{"readyState":0,"status":0,"statusText":"timeout"}

哪位大神遇到過，麻煩你看看。在此表示感謝！