Abstract: The mechanism of set out violent slide of slope mass during earthquake is discussed in the paper. The authors study suggests that there are three effects of the slope mass vibration in its deformation and failure process during earthquake. They are progressive failure, set out slide, and acceleration effects. By using discrete element method, the processal of deformation and failure of Luotuoling landslide is simulated. The obtained result is of theoretecal and practical signifiance.