Abstract: Accumulation landslides located in the Southwest Mountainous are affected by both earthquake and heavy rainfall, the deformation and failure characteristics of landslides are affected by these two main factors. Finding out the deformation and failure mechanism of this kind of landslide is the basis of geological disaster prevention and risk prevention and control. This paper takes Maju landslide in Luhuo County as the research object. The results show that, the seismic action has obvious damage effect on the structure of accumulation landslide located in slope zone, it not only reduces the overall stability of the landslide, but also promotes the development of a large number of fissures in the slope, which is conducive to the infiltration of rainfall into the slope, and then worsens the hydrogeological conditions of the landslide. Heavy rainfall is easy to form large-scale flood and debris flow, cutting the gully at the foot of the slope, and pulling the landslide to slide downward as a whole. The long-term heavy rainfall infiltration slope also has a great impact on the stability of the landslide, and the landslide is in an unstable state for a long time after rainfall. Therefore, for this kind of landslide prevention scheme, the strategy of paying equal attention to slope toe protection and anti slide retaining should be adopted, the effectiveness analysis of the protection scheme shows that the safety of the protection scheme has a certain guarantee under extreme conditions, achieves the purpose of prevention and control, and further controls the risk.