Change the data type of post to formdata, and then load the object in formdata. The following is an example:

    var fd = new FormData();
    var file_data = $('input[type="file"]')[0].files; // for multiple files
    for(var i = 0;i<file_data.length;i++){
        fd.append("file_"+i, file_data[i]);
    }
    var other_data = $('form').serializeArray();
    $.each(other_data,function(key,input){
        fd.append(input.name,input.value);
    });
    $.ajax({
        url: 'caiyongji.com/segmentfault',
        data: fd,
        contentType: false,
        processData: false,
        type: 'POST',
        success: function(data){
            console.log(data);
        }
    });

You have already created the new FormData, so don’t save objects by yourself. Just use the new one...

mui.init();
function fsubmit() {
    var fData = new FormData(); //这里用空的就行，后边再append
    fData.append('file', mui('#uploadForm')[0], '不知道你文件名是啥你自己去整下.jpg');
    fData.append('key', localStorage.getItem('key')); //获取本地的登录令牌
    $.ajax({
        url: 'http://192.168.1.8/api/user-center/avatar',
        type: 'POST',
        data: fData,
        processData: false,
        contentType: false,
        success: function (data) {
            console.log(data.datas.testURL);
        },
        error: function (xhr, type, error) {
            console.log(xhr.status + xhr.responseText);
        }
    });
    return false;
}

Then the backend is slightly adjusted to be able to receive FormData.

Thanks for the invitation:

Token can be placed in headers, and the backend checks the token separately, while this interface only processes images