Based on the design of Jinghong ship-lift,this article expounds the functions of all subsystems of mechanical system & components of hydraulic ship-lift,reseasrches the structure & design parameters of the ship-lift,and proposes the main structure & design parameters of the drum,the synchronizing system,the float,the fall block device,the wire rope assembly and the water-entering navigation chamber.Probing into details in adding water of the float,this paper puts forward the novel-innovative structure for the gapless synchronizing system and the sealing device which is used for the navigation chamber docking,providing reference for the similar engineering design.