Abstract: In view of the adverse effect of excavation and unloading on Chefengping accumulation slope, the inequality considered in material friction angle and Poisson's ratio was introduced to improve discrete element strength reduction method. The improved discrete element strength reduction method was used to calculate the safety coefficient, analyze the simulated excavation deformation of the slope and the displacement variation of the feature points, and evaluate the stability of the slope in each step of excavation, and the reinforcement measures of anchor cable support were formulated. The results show that the slope safety coefficient calculated by the improved discrete element strength reduction method is slightly conservative, and the calculated results are relatively safe. In the process of excavation, accumulation body slope is unstable, such as sliding and shifting platform. With the reinforcement method of anchor cable support, the safety coefficient of the accumulation body slope in all working conditions is improved, and the construction risk is reduced. The displacement of feature points of the first three steps is reduced by about 90%, and that of the second two steps is reduced by about 30%.