Abstract: Research on the grading of impact risk is an important prerequisite to dealing with the danger of impacts by near-asteroids. In this paper, a new risk-grading method was proposed to estimate the risk of near-Earth asteroid impact. The hazard forms and consequences of near-Earth asteroid impact were analyzed, and the factors of impact risk classification were sorted out. The relatively mature Torino scale model and Palermo index model were discussed, and the equivalent diameter and impact probability were taken as the main factors to design the impact risk grading method. A refinement of partition model of risk grade was established. Finally, the simulation comparison and analysis were carried out for different risk grading models.