The invention discloses a cleaning device for a mooring rope and a roller thereof, wherein the roller can roll along the mooring rope, a slot is formed in a rolling surface of the roller contacted with the mooring rope and is parallel to the rotating shaft of the roller, the middle of the rolling surface of the roller is lower than the two sides, and a cambered surface is formed by the higher places and the lower places of the two sides of the rolling surface. The slot is formed in the roller of the cleaning device for the mooring rope, so as to clean attachments on the mooring rope; an elastic part is increased to adjust the pressing force of the roller on the mooring rope, so that the attachments on the mooring rope can be cleaned well; the elastic part can be effectively adjusted by a pressure adjusting limit member, the position of the pressure adjusting limit member can be adjusted but the elastic part can not be changed if the elastic performance of the elastic part is reduced.