假设您有一个表单：

<form name="post" id="post-form" action="" method="post" enctype="multipart/form-data">
    <input type="text" name="first_name">
    <input type="text" name="last_name">
    <input id="file" type="file" name="featured_image">
</form>

jQuery(document).ready(function($) {
    $(\'#post-form\').submit(function(e) {
        e.preventDefault();
        var form = $(this);

        file_data = $(\'#file\').prop(\'files\')[0]; //get the file
        form_data = new FormData(); //form_data is a FormData() object 
        form_data.append(\'featured_image\', file_data); //append the file in form_data object
        form_data.append(\'action\', \'insurance_form_data\'); // your wordpress function name
        form_data.append(\'post_data\', form.serialize()); // e.g. other form data such as first_name, last_name will be stored as serialized

        $.ajax({
            url: \'/wp-admin/admin-ajax.php\',
            type: \'POST\',
            contentType: false,
            processData: false,
            data: form_data,
            success: function(response) {
                console.log(response);
            },
            error: function(xhr, status, error) {
                console.log(error);
            }
        });
    });

});

function insurance_form_data() {
    print_r($_POST);
    print_r($_FILES);
}