To the problems of crossflow and backflow exceeding the standards in the entrance area of approach channel for mountainous sharp bends,especially in sharp bend sections of mountainous area,this study uses physical model experiments to investigate the influence of diversion piers layout on navigation flow conditions in the entrance area of the ship lock approach channel.Taking the Meitan ship lock in Xin'an River as the research object,this paper comprehensively considers multiple parameters such as pier type,layout angle,pier dimensions,pier spacing and piers quantity，and focuses on analyzing the water flow state under different pier spacing and pier quantity conditions.By comparing hydraulic indicators such as longitudinal flow velocity,transverse flow velocity,and backflow velocity in the entrance area,the layout of diversion piers is optimized.The results show that the diversion pier geometry can be designed as a parallelogram,and the layout angle should be arranged parallel to the navigation channel.Additionally,the central axis of the inter-pier spacing should be arranged at an acute angle with the water flow direction.For sharp bend sections,the relative spacing between the diversion piers is set to 0.50 times the pier length,and the number of diversion piers is not less than 5.The protection range should extend to the middle section of the entrance area,which can effectively improve the navigation flow conditions in the entrance area of the approach channel for the Meitan ship lock.