KUKA 30-3 robot is employed as the experimental platform. Robotic automation grinding and polishing ( RAGP) of polymethylmethacrylate ( PMMA) are investigated based on the force control technology. By the analysis of theory,the important effect factor of PMMA surface quality is the contact force between the GP tool and the surface of workpiece surface. However,robot based on force control can imitate worker’s operation,and keeps the contact force between GP tool and surface constant to obtain better surface quality. PMMA is taken as the experimental material. The surface quality effect of the different GP force is investigated with or without force control. The experimental results show that robotic grinding and polishing process with force control not only improves surface quality,but also increases efficiency and guaranteed the uniformity of product quality.