Aiming at the problems such as uneven distribution of the approach channel along the lateral and heavy load on ships in the berthing section when the downstream approach channel of ship lock is arranged asymmetrically,the water level fluctuation characteristics,surface flow field structure and ship stress characteristics in the downstream approach channel during the unsteady flow of ship lock are studied.Based on a typical ship lock project,the whole hydraulic physical model of ship lock with a scale of 1:30 is studied.The test results show that,in view of the overall layout of the asymmetric approach channel,the combined arrangement of the sill in the discharge channel should also be asymmetric,so as to adjust the transverse shunt ratio in the approach channel,and the sill should not be too close to the drainage outlet,so as to avoid the flow blocking effect.Under the premise of not producing backflow,appropriate reduction of the side flow of the berthing section can significantly improve the conditions of the ship's berthing stability.The research results can provide reference for the design and research of energy dissipator of ship lock approach channel and outlet.