Abstract: TheThe process of an asteroid impacting the land is a complex non-linear dynamic process, which is difficult to study by using model tests. Numerical simulation provides an important tool for the analysis of this process. In this study, the large-scale numerical simulation of the dynamic process of the asteroid impacting land was realized initially by using the self-developed software CoSim-DEM based on the discrete element method (DEM). Based on the numerical simulation results, the four stages of the impact process—initial contact, impact excavation, high-speed ejection and adjustment—were simulated; the incidence angle and the dynamic behaviors of the asteroid during the impact process would affect the topographic characteristics of the crater. This study also indicates that large-scale numerical methods can be used to perform the analysis of dynamic process of the asteroid impacting the earth, and provide support for asteroid defense.