解决方法：添加
contentType : ‘application/json‘,
$.ajax({ type: "POST", url: "/xxx", dataType:‘json‘, contentType : ‘application/json‘, async : ‘false‘, data:{"name":1,"value2":2}, success:function (data) { } });
原文：https://www.cnblogs.com/passedbylove/p/12509839.html