Abstract:processing non planar or non cylindrical surface of workpiece, flexible grinding machine must be used. Two kinds of flexible grinding machine were designed, namely circular flexible grinding machine and tooth flexible grinding machine. The grinding device was sealed rubber wheel which interior was filled water, exterior was pasted gravel. According to the Pascal principle, any part of the sealed waterfilled rubber wheel pressure was equal. The shape where rubber wheel contacted workpiece could be changed with the shape change of the workpiece surface, but contacted point pressure of rubber wheel and workpiece was equal anywhere, so any part of the workpiece contacted with rubber wheel would be smoothly grinded.