请求

var form = new FormData(document.getElementById("background-form"));
$.ajax({
    url: ctx + "/dept/upload",
    type: "post",
    data: form,
    processData: false,
    contentType: false,
    success: function (data) {
        console.log("over..");
    },
    error: function (e) {
        console.log("over..");
    }
});