【正文】 technology can be used in preparation of optical free form surfaces element Slow Tool Servo and Fast Tool Servo are the develop faster ultraprecision processing technology in the rencent , the two kind of technology can significantly improve the microstructure are arrays and free surface optical device processing efficiency. Slow Tool Servo is on the lathe spindle and turning the Z axis are control, make the spindle into position controllable C axis, machine Tool of the X and Z, C three axis in the space form the cylindrical coordinate system, at the same time, high performance and high programming of CNC system will resolution plex face form ponents of the threedimensional cartesian coordinate into polar coordinates, and all moving axis to send interpolation into to instructions, precise coordination shaft and the relative motion of the cutting Tool, and to realize the plex face form of turning machining parts. Slow knife servo turning the Z axis X axis and often also make sine reciprocating motion, requires multiaxis interpolation linkage. Therefore, in the process of parts required before more face form the analysis of the coordination between the shaft, then determines the tool path and cutting tools pensation. In addition, slow sword by machine tool servo slide inertia and response speed and motor to influence is bigger, machine tool dynamic response speed is low, suitable for processing face form and larger plex for optical device. Fast Tool Servo turning and slow knife Servo differ in that will be processing plex shape face turning into shape face and form the microstructure of the surface, and then will both stack. The X axis and Z axis to realize the turn into shape trajectory, lathe spindle of only position detection do not track control. With installed in the Z axis but independent of CNC outside the system of redundancy axes to drive the cutting tools, plete turning the surface microstructure form the Z axis movement. The processing method has high frequency, high stiffness, the characteristics of high precision. Diamond tools in piezoelectric actuators can be under the reciprocating movement of the Z axis. Control system in realtime acquisition spindle Angle signal, and on the basis of realtime sends out of control, realtime control tool to micro into, so as to realize the cutting tool tracking face form the rise and fall of the change. A sharp sword servo in processing only for parts before face form for accurate calculation, gen