Abstract: In order to improve the property and the efficiency of traditional removal function of small tool polish, ellipse motion method was achieved through three-rotor movement on the basis of planet motion. Then, a new removal function was investigated and deduced based on the assumption of Preston. At last, the surface matrix of removal function was calculated by computer and after optimization. The final parameters and the removal function which was close to the ideal Gaussian function were obtained. The results show the removal efficiency of ellipse motion is better than planetary removal's. Removal function based on ellipse motion can avoid the defect of previous function of planet motion and increase the removal efficiency during polishing process.