For the advantages of correcting aberration and simplifying optical system, aspheric parts are widely used in modern optical instruments, and one of the most widely used aspheric part is two axisymmetric aspheric surface. The method of grinding and trimming for processing two axisymmetric aspheric surfaces is researched, which is the method of grinding and trimming aspheric surfaces based on recent spherical surface. From the aspheric equation, the recent spherical surface and the deviations of the zones are obtained to determine the processing scheme. And the required aspheric process is obtained using appropriate trimming tools.