In order to study the force of shallow-water wave on coastal buildings under extreme conditions,we apply physical model test to carry out a series of experiments on overtopping discharge and force of vertical-wall attached on sloping seawall in the wave flume,obtain the pressure distribution of the vertical-wall on seawall,and get the relationship between overtopping discharge,pressure and velocity based on the momentum equation.The results show that the impact force on the vertical-wall under different conditions presents different trends.It presents a single-peak evolution shape when the overtopping discharge is little,and it presents a double-peaked evolution shape when the overtopping discharge is large.The horizontal force of the overtopping flow on the vertical-wall is consistent with the Weibull distribution.The uplift angle increases first with the increase of overtopping discharge,and it decreases slightly with the increase of overtopping discharge when overtopping discharge is large.The maximum uplift angle of overtopping is about 75°.