Abstract: In view of the problem that it will induce disasters if heavy rainfall influences the waste dump with complex terrain in a mine, four kinds of heavy rainfalls with return period of 100 years are designed. With the help of modeling function of ANSYS, a complex model for the dump is established. Utilizing the fluid-solid coupling module of FLAC^3D, four kinds of heavy rainfalls are imposed on the dump, respectively. It uses two criteria, whether plastic deformation area cuts through the dump and whether displacement value of representative position uprushs, to judge whether or not failure of the dump occurs. The results show that, the waste dump will slide in the case of rainfall if its intensity is larger than 5 mm/h and its duration is longer than 40 minutes. This study may provide theoretical and technical support for the mine to prepare for risk prevention.