试试这个逻辑:-

function music_meta_box( $post )
{
    // Get post meta value using the key from our save function in the second paramater.
    $custom_meta = get_post_meta($post->ID, '_custom-meta-box', true);

    ?>
        <input type="checkbox" name="custom-meta-box[]" value="huge" <?php echo (in_array('huge', $custom_meta)) ? 'checked="checked"' : ''; ?> />Huge
        <br>
        <input type="checkbox" name="custom-meta-box[]" value="house" <?php echo (in_array('house', $custom_meta)) ? 'checked="checked"' : ''; ?> />House
        <br>
        <input type="checkbox" name="custom-meta-box[]" value="techno" <?php echo (in_array('techno', $custom_meta)) ? 'checked="checked"' : ''; ?> />Techno<br>
    <?php 
}
add_action( 'save_post', 'save_music_meta_box' );
function save_music_meta_box()
{

    global $post;
    // Get our form field
    if(isset( $_POST['custom-meta-box'] ))
    {
        $custom = $_POST['custom-meta-box'];
        $old_meta = get_post_meta($post->ID, '_custom-meta-box', true);
        // Update post meta
        if(!empty($old_meta)){
            update_post_meta($post->ID, '_custom-meta-box', $custom);
        } else {
            add_post_meta($post->ID, '_custom-meta-box', $custom, true);
        }
    }
}

希望对你有帮助.