In order to better study the mechanism of laser polishing,the mechanism of laser polishing based on Gauss heat source is introduced.The mathematical modeling and analysis of the change process of material surface topography are carried out.The surface topography model is described theoretically.The curve integral method of two-dimensional projection of three models is used to fit the material surface profile,and the method of calculating transition surface is proposed.The modeling object is extended from a single peak to the whole facula range.The z-axis change of the surface is fitted by the method of heating and stripping after the external normal direction irradiated by directional energy.The surface roughness after polishing is predicted by the change of z-axis.Laser irradiation simulation was carried out using ANSYS to simulate the surface of materials with different morphologies.The results show that the temperature changes with time under various surface conditions and different surface morphologies of materials have a great influence on polishing effect.