闭门造车（閉門造車）　

◎ 闭门造车 bìmén-zàochē

[make a cart behind closed doors;divorce oneself from reality and act blindlly] 原指按同一规格,关起门来造车。用起来也很合辙。后反其意而用之,比喻自作主张,不合实际

脱离实际,闭门造车,是创作不出好作品的