Abstract: In this study,coupling CFD and sediment-laden two-phase flow method,a three-dimensional scour model is proposed. The scouring mechanism of wind turbine foundation is revealed base on offshore wind farm in Rudong. Numerical results show that:1)the model can emulate the flow field characteristics around the pile well;2)The scouring patterns are good in agreement with the on-site monitoring results;3)The scouring depth and shape for Rudong offshore wind farm foundation are mainly controlled by the tidal velocity and duration;4)The scour on both sides of the pile is more serious,and the scour pit range is about 2-4 times pile diameter.