The coupling analysis of slope runoff and infiltration under rainfall is one of the important key problems for the research of rainfall-induced landslides and the soil conservation. The subsurface and surface flow coupling equation is established; and the solution can be achieved directly by the method of FEM. Using the method
it is not necessary to calculate the moisture flux that passes the slope surface; and then the computational precision and the computational speed can be improved. The simulation results show that the method is feasible