Three dimensional numerical simulation of water flow in a curved channel is carried out,and the flow characteristics flow in the bend channel are briefly analyzed.By coupling the water erosion with two-dimensional numerical simulation of slope stability,the effect of water erosion on the stability of bank slope was quantified,and the slope stabilities under different scour depths were calculated.The results show that the slope is affected by water erosion more with high water level;The greater the scour depth,the smaller the slope stability coefficient is.The local bank slope collapses to lead to lower stability when the erosion reaches a certain degree.