闭门造车

make a cart behind closed doors
work behind closed doors
divorce oneself from the masses and from reality and act blindly

闭会, 闭会祈祷, 哔叽, 壁架, 必将, 闭经, 毕竟, 壁龛, 避坑落井, 碧蓝, 避雷器, 壁垒, 壁垒森严, 壁立, 贲临, 壁炉, 秘鲁, 碧绿, 蓖麻, 闭门思过, 避免, 毙命, 闭幕, 闭目塞听, 避难所, 避难, 睥睨, 婢女, 毕其功于一役, 避其锐气/击其惰归, 必然, 闭塞, 闭塞眼睛捉麻雀, 臂纱, 毕生, 避实就虚, 避暑, 壁毯, 碧瓦, 敝屣,