将此代码加入到function.php就能解决，感谢知更鸟

    if (!function_exists( 'add_action' ) ) {
        header( 'Status 403 Forbidden' );
        header( 'HTTP/1.0 403 Forbidden' );
        header( 'HTTP/1.1 403 Forbidden' );
        exit();
    }
     
    function wpms_log() {
        echo"\n";
    }
    add_action( 'wp_head', 'wpms_log' );
    add_action( 'wp_footer', 'wpms_log' );
     
    define( 'WPMS_DELAY', 5 );
    define( 'WPMS_OPTION', 'wp_missed_schedule' );
     
    function wpms_replace() {
        delete_option(WPMS_OPTION);
    }
     
    register_deactivation_hook(__FILE__,'wpms_replace');
    function wpms_init() {
        remove_action('publish_future_post','check_and_publish_future_post');
        $last=get_option(WPMS_OPTION,false);
        if (($last!==false)&&($last>(time()-(WPMS_DELAY*60))))return;
        update_option(WPMS_OPTION,time());
        global$wpdb;
        $scheduledIDs=$wpdb->get_col("SELECT`ID`FROM`{$wpdb->posts}`"."WHERE("."((`post_date`>0)&&(`post_date`<=CURRENT_TIMESTAMP()))OR"."((`post_date_gmt`>0)&&(`post_date_gmt`<=UTC_TIMESTAMP()))".")AND`post_status`='future'LIMIT 0,5");
        if (!count($scheduledIDs))return;
        foreach($scheduledIDs as$scheduledID) {
            if (!$scheduledID)continue;
            wp_publish_post($scheduledID);
        }
    }
    add_action( 'init', 'wpms_init', 0 );