尝试以下操作：

<div class="my-metabox">
    <!-- This is your metabox HTML -->

    <-- Add this button somewhere: -->
    <button id="my-submit" class="button button-primary button-large">Submit</button>
</div>

根据需要添加此JavaScript片段only to this screen （通过检查帖子类型并将其列在管理页脚中，或直接将其与metabox HTML一起输出）：

<script type="text/javascript">
    jQuery(function($) {
        // You can substitute this with a CSS rule somewhere:
        // <style type="text/css"> #submitdiv { display: none } </style>
        // if you wish to avoid the hiding \'flicker\'
        $(\'#submitdiv\').hide();

        $(\'#my-submit\').on(\'click\', function(ev) {
            ev.preventDefault();                
            $(\'#publish\').trigger(\'click\');
        });
    });
</script>