Working functions of the small polishing pad that works in two motion models are discussed in the process of computer controlled optical polishing, one model is planet motion, the other is translation. Also, The wearing distribution of the polishing pad in two motions is introduced. At last, the performance curve and wearing distribution curve of the polishing pad are worked out by computer simulation. By means of analyse and comparison in two model simulation results, a better motion model is selected to be used in future process of computer controlled optical polishing.