Abstract:The traditional method of complex surface machining is usually machined under the constant polishing force and constant polishing path, or through the adjustment of pressure to achieve equal pressure at the time of processing, the purpose of all is just to achieve a constant amount of material removal. Moreover, the ideal complex surface is only achieved through the detection and multiple cycle of polishing processing, and the machining efficiency is a little low.Based on the Preston theory, a new method is presented for machining complex surface that is grinding and polishing force control technology in order to solve the problem of low machining efficiency. Based on five axis ultra precision grinding and polishing machine tool as the experimental platform, the workpiece could be machined like manual processing under this technology, and was achieved in the removal of polishing allowance while eliminating the errors of the curved surface shape. In the experiment,the workpiece of K9 glass was machined using this method, its range of surface roughness Ra value changes stably between 0.011~0.024 μm after polishing. Processing efficiency is improved significantly compared with the traditional method of the constant force, which shows the effectiveness of the new method.