Abstract: Computer Controlled Surface Processing(CCOS) technology has been widely and successfully applied to the manufacture of optical components. In typical extreme optical manufacturing engineering, smoothing the surface errors is a very important process. Based on Presston equation, the tool influence function (TIF) of polishing pad is modeled, and the theoretical expression of TIF is obtained. Based on the parametric smoothing model, a multi-parameter time-dependent theoretical model is established. The results show that the surface error of components converges exponentially with the polishing process, and the convergence efficiency depends on the polishing parameters such as material parameters and volume removal rate. The smoothing curve of the theoretical model is simulated and analyzed, and the smoothing efficiency under different technological conditions is compared. The results show that the higher the material coefficient is, the higher the overall smoothing efficiency is. Similarly, the larger the volume removal rate of the polishing pad, the higher the smoothing efficiency of the surface error. A series of smoothing experiments with 3, 5 and 7 mm ripple errors were carried out. The results show that under the same polishing parameters, the smoothing efficiency of ripple with larger spatial frequency will be higher and the convergence curve will decline faster. Finally, the smoothing efficiencies of different material are compared, and the experimental results show that the smoothing efficiency of pitch pad is much higher than that of polyurethane polishing pad.