问python里Post发送请求错误，新手上路，请大神指导。？

https://zlaq.mohurd.gov.cn/fwmh/bjxcjgl/fwmh/pages/construction_safety/qyaqscglry/qyaqscglry.html

这个网址用requests爬取查验一个叫张三，证号321123196104179999的人员，

检查载荷表单数据为：{"pageIndex":"0","pageSize":"10","search":"","totalSearch":"{\"xm\":\"张三\",\"sfzjhm\":\"321123196104179999\",\"aqscglrylx\":\"\",\"aqsckhhgzsbh\":\"\",\"province\":\"\",\"city\":\"\",\"district\":\"\",\"sfzjlx\":\"\",\"zszt\":\"\"}","searchtype":"fwmh"}

使用Post上载，试了三种方法，用data= 和Json= 上载都不行，新手上路，请大神指导。

"pageIndex":"0",

"pageSize":"10",

"search":"",

"totalSearch":{"xm":"张三

","sfzjhm":"321123196104179999","aqscglrylx":"","aqsckhhgzsbh":"","province":"","city":"","district":"","sfzjlx":"","zszt":""},

"searchtype":"fwmh"

*************************************************状态400

{"pageIndex":"0"},

    {"pageSize":"10"},

    {"search":""},

    {"totalSearch":{"xm":"张三

","sfzjhm":"321123196104179999","aqscglrylx":"","aqsckhhgzsbh":"","province":"","city":"","district":"","sfzjlx":"","zszt":""}},

    {"searchtype":"fwmh"}

***************************************状态400

"params":"%7B%22pageIndex%22%3A%220%22%2C%22pageSize%22%3A%2210%22%2C%22search%22%3A%22%22%2C%22totalSearch%22%3A%22%7B%5C%22xm%5C%22%3A%5C%22%E5%BC%A0%E4%B8%89%5C%22%2C%5C%22sfzjhm%5C%22%3A%5C%22321123196104179999%5C%22%2C%5C%22aqscglrylx%5C%22%3A%5C%22%5C%22%2C%5C%22aqsckhhgzsbh%5C%22%3A%5C%22%5C%22%2C%5C%22province%5C%22%3A%5C%22%5C%22%2C%5C%22city%5C%22%3A%5C%22%5C%22%2C%5C%22district%5C%22%3A%5C%22%5C%22%2C%5C%22sfzjlx%5C%22%3A%5C%22%5C%22%2C%5C%22zszt%5C%22%3A%5C%22%5C%22%7D%22%2C%22searchtype%22%3A%22fwmh%22%7D"

**********************************状态200，传入的json参数不规范