The utility model discloses a ceiling of a ship, and relates to the ship, in particular to a collapsable ceiling on the ship. The collapsable ceiling comprises a ship body and a deck, and further comprises a ceiling, wherein front upright posts are mounted at the front part at the lower end of the ceiling; rear upright posts are mounted at the rear part at the lower end of the ceiling; the front and the rear upright posts are fixed on the ship body through rotating shaft seats; the ceiling is fixed through a ceiling bracket; side plates taking the shape of the curved surfaces of cams are mounted on two sides of the ceiling bracket; a guide groove is formed on each side plate; a guide roller is mounted in each guide groove and can move in the guide groove to realize the expansion and the contraction of the ceiling; and rollers capable of rolling on the curved surfaces of the side plates are mounted on the rear upright posts. The collapsable ceiling has the advantages that the expansion and the contraction of the ceiling are controlled in an unmanned manner; and the ceiling is kept level during the expansion and the contraction.