The impact process of a large-sized high-speed landslide against the mountain body is analyzed theoretically with mechanical principles. A then the expression of average velocity and moving direction of the landslide rock-mass after impact are obtained. Through the impact experiments

the effect of acceleration motion of partial rock mass after impact is also studied. Finally

the volumetric distribution law of various segments with different velocities after impact is obtained. The results will be useful for reducing and preventing disasters.