这个问题是因为第一个“if”，好的文本字段中只设置了第一次

要改变这一点，您可以在HTML中添加一个“data”参数，并像这样更改JavaScript代码（查看中的修改meta_image_frame.on(\'select\'...)

(function($) {
    \'use strict\';

    $(function() {

        var meta_image_frame;

        function saveImage(e, uiElement) {

            e.preventDefault();

            if (meta_image_frame) {
                meta_image_frame.field = $("#" + $(e.target).data("field"));

                meta_image_frame.open();
                return;
            }

            meta_image_frame = wp.media.frames.meta_image_frame = wp.media({
                title : "meta_image.title",
                button : {
                    text : "meta_image.button"
                },
                library : {
                    type : \'image\'
                }
            });

            meta_image_frame.on(\'select\', function() {
                var media_attachment = meta_image_frame.state()
                        .get(\'selection\').first().toJSON();
                meta_image_frame.field.val(media_attachment.url);
            });

            // Opens the media library frame.
            meta_image_frame.open();

        }

        $(\'#fa_img1-button\').click(function(e) {
            saveImage(e, \'#fa_img1\');
        });

        $(\'#fa_img2-button\').click(function(e) {
            saveImage(e, \'#fa_img2\');
        });

    });

})(jQuery);

<input id="fa_img1" type="text" value=""/>
<br/>
<input id="fa_img1-button" type="button" data-field="fa_img1"
    value="Upload Image"/>
<br/>
<br/>

<input id="fa_img2" type="text" value=""/>
<br/>
<input id="fa_img2-button" type="button" data-field="fa_img2"
    value="Upload Image"/>
<br/>
<br/>