Abstract: To analyze the influence of edge effect on the accuracy of workpiece final surface, two models of removal functions are built in this study, one is the model of planet motion of computer controlled optical surfacing, the other is of jet polishing. By investigating the microscopic state of grinding compound carrier, the distribution of polishing velocity and stress and the variation of Preston parameter in two models were simulated and analyzed. The influence of above factors on material removal was revealed. The result indicates that the force between the molecules of the grinding compound carrier have a great influence on edge effect in optical processing.