The removal performance of optical materials by ion beam sputtering is investigated in this paper. the bombardment process of Ar+ and Kr+ was simulated through the software TRIM. It is feasible to achieve a high removal rate by using Ar+ ion beam with a big incident angle, which demonstrates that the material removal sputtering yield rises up with the increase of the incident ion energy and incident angle within a certain range. The material removal principle is of great significance to the further performance application of the ion processing in the field of optical processing.