A new method to improve engine camshaft grinding efficiency and processing accuracy was proposed on the basis of maximum allowable angle steps. The angle step value was calculated from the local curvature of grinding wheel center motion curve relative to camshaft processing angle. Then, the cam was processed segmentally to optimize its processing angle step and speed. Compared with constant angular velocity grinding, this new method can reduce superfluous steps and increase manufacture efficiency. Moreover, it can also improve the processing accuracy and avoid the response lag on buffer portion linking to ascent portion and descent portion of cam.