A flume test is used to analyze the surface wave force and porewater pressure on the bank slope of a reservoir under different conditions. On the basis of the experiment result, it shows that roughness coefficient and permeability coefficient are the more important factors influencing the wave force of bank surface, and that the wave steepness, relative position along the depth and permeability coefficient are close relative with the porewater pressure. Simultaneously, the pore water pressure will be attenuated in amplitude and lagged in phase with increase of water depth.