Wenchuan earthquak induced a large number of mountain hazards. Through the survey found that manual excavation slopes tend to become concentrated area of mountain disaster, it’s indicate that the effect of excavation damage on the slope deformation and failure under seismic load is very obvious. Anti-dumping slope deformation as one types of mountain hazards induced by Wenchuan earthquake, and it’s also seriously affected by excavation damage. In this paper, as Wang Jiaping landslide for example, using the finite element method to simulate the landslide and analysis the deformation and failure of slope affected by the excavation damage. Analysis shows that deformation and failure of slope is significantly induced by excavation, and resulting in displacement, stress and the between layer sliding distance increased，the between layer friction stress reduced. The results agreement with the characteristics of the anti-dumping slope deformation and failure induced by Wenchuan earthquake mainly concentrated in excavation slopes.