Abstract: According to current requirements of efficient and precision machining for spherical parts which are made with difficult-to-machine materials and used in aerospace,high-speed rail and other industrial fields,the machining principle and method for spherical parts are introduced briefly.Three traditional spherical grinding methods are analyzed for their advantages and disadvantages.Then a new spherical grinding method is proposed based on the principle of grinding wheel normal tracking to improve the efficient precision machining for spherical parts and take full advantage of multi-axis grinding machine.It is divided to cylindrical-like grinding and plane-like point grinding according to motion decomposition.In view of geometry contact length between grinding wheel and workpiece and grinding wheel cutting path,the geometry and kinematic model is analyzed,so as to provide guidance for further study.