The Dongxi sluice section of the Chaozhou water supply project is characterized by a C-shaped curved channel.The new ship lock is arranged on the convex bank of the curve,and the angles between the center line of upstream and downstream approach channel and river are very large.Through the physical model and ship model test,concrete measures to improve the flow conditions are put forward.The results show that through the measures of reducing navigation standard,optimizing routes,and excavating and adjusting convex shoreline,the angle between the center line of approach channel and the main stream is reduced,and the adverse flow patterns such as lateral velocity and return flow in upstream and downstream approach channel and entrance area are weakened.The navigation flow conditions of Dongxi lock are effectively improved,which can provide reference for the layout of similar types of ship lock.