A typical cross-section of the downstream separation levee for the ship lock reconstruction project of Guo River navigation channel is selected.Based on the solid mechanics interface of COMSOL Multiphysics and the interface between porous media and groundwater flow,the flow-solid coupling analysis of the separation levee model is carried out to investigate the effects of stress,head pressure and stability of the separation levee under the conditions of different water level heights.The results show that under the effect of flow-solid coupling,the maximum Mises stress of the separation levee occurs at the junction of the silt layer and silty clay layer with the steel sheet pile,and the maximum Mises stress value is 19.20 MPa.The water head pressure of the separation levee increases with the rise of the water level.When the water level is 8 m,the maximum head pressure occurs in the silt layer a at the bottom left of steel sheet pile 1,with a water head pressure of 24.88 m.The strain and displacement of the separation levee increased continuously with the rise of the water level.When the water level rises to 8 m,the maximum displacement of the separation levee reaches 253.90 mm,and the soil at the top of the embankment slides 1.20 mm towards the rear side of steel sheet pile 2.At this time,the maximum volumetric elastic strain and the equivalent deviatoric strain are 9.16% and 11.03% respectively.The seepage barrier effect of the steel sheet piles is verified through simulation models,and the sliding position and water level of the separation levee with the rise of water level are predicted,providing a reference basis for the smooth implementation of the ship lock reconstruction project of the Guo River navigation channel.