Atmospheric plasma machining is a kind of processing technology aimed to super-smooth surface. But it has the problem that there is the deposition in the optical surface after processing. In this paper, through orthogonal experiments, it is verified that the quality of the optical surface can be improved by increasing the initial temperature and removal depth of the optical surface. It is also shown that the initial temperature of the optical surface can be improved and the removal depth can be improved by multiple processing. The experimental results show that the surface quality can be improved by multiple machining with a certain volume removal rate, and the roughness Ra is reduced from 8.48 nm to 2.78 nm.