To optimize the design of the Xinsanjang Ship Lock,a physical model test study is carried out on the local movable-bed on the Cao’e River side of the Xinsanjang Ship Lock.According to the terrain of the project reach and the project layout,the model scale is determined,the model sand is selected,and the model similarity is verified.The test adopts the water and sediment conditions of a series of years and typical flood years to conduct a local movable-bed erosion and deposition test on the recommended plan,and studies the laws of sediment erosion and deposition and their impacts on the channel scale and navigable flow conditions.The results show that after the optimization scheme adjusts the diversion wall at the entrance of the lower approach channel to an arc-shaped gradually expanding trumpet shape,the navigable flow conditions of the lower approach channel and the entrance area of the ship lock under different flow conditions are significantly improved.The erosion and deposition rate in the series-year test tends to slow down with the increase of years.The difference in the erosion and deposition rate at the end of 10 years in the upstream reach of the ship lock is reduced to 2,800 m3/(km·a),approaching the erosion and deposition balance.The research results can provide a basis for the design optimization of the ship lock and the regulation of the waterway.