This article introduces the characteristics of the hydraulic ship-lift,and discusses the key technology for hydraulic ship lift design.The hydraulic ship lift is safe and reliable,and can adapt to the large variation range of the downstream water level.This article focuses on the key technology of the filling and emptying system,mechanical system,and the status when the tank entering or leaving the water.It is pointed out that the filling and emptying system should focus on the synchronization of vertical shaft water level and the water flow control,the mechanical system should focus on the no-gap transmission and adaptation to the base deformation,and when the tank enters or leaves the water,the unbalanced loads need to be focused.