This paper sets up a two-dimensional current numerical model using the MADI finite difference method,applies the moving boundary to solve the problem of mobile boundary with the water level,and conducts a numerical model to simulate tidal current of the engineering area.In order to research further the tidal field research,this paper uses two sets of grid computing solutions and refined grids.The result and its verification show that the calculated process of the tidal level and current coincide fairly well with the field data,and it provides a scientific basis for the development of Hailong bay.