The docking process is an important part in the whole process of ship lift operation.The fluctuation of water surface in the ship chamber during docking directly affects the safe docking of the ship and the working conditions of the synchronous shaft of the hydraulic ship lift.Aiming at the influence of the fluctuation characteristics of the water surface inside the ship chamber on the safe operation of the ship lift during this process,the 500 t class ship prototype test of opening and closing the horizontal door at different docking water levels and the ship entering and leaving the tank at different speeds is carried out.The effects of the docking water level and the speed of the ship entering and leaving the chamber on the characteristic of the water surface fluctuations in the tank are mainly discussed.The empirical formulas for the amplitude of the fluctuations in the ship chamber and the difference in water depth and water level are given to analyze its impact on the safety of tank and ships.The test results verify the navigation safety of the 500 t class ship of Jinghong ship lift.