Abstract: As the demand for freeform optical component processing continues to grow, ultra-precision grinding and polishing equipment and processes that offer short cycle times, high flexibility, and intelligence are becoming crucial for the mass production of optical components. Traditional ultra-precision grinding machines have long design cycles, high manufacturing and investment costs, and struggle to meet the diverse needs of small and medium-sized custom applications. Based on a six-axis industrial robot with large working space, low cost, intelligence and flexibility, a robot active flexible force control grinding method was proposed to explore the motion control of machine manual control grinding operations, and study the characteristics of force control flanges to master the force control control strategy. The stable grinding force model was established based on the solution of the force controlled grinding process experiment to realize the constant grinding amount of the robot by controlling the expected force, and the surface shape quality of the workpiece was effectively improved in the rough grinding stage. Compared with the robot's weak control grinding, the peak-to-valley (PV) of the machine manual controlled grinding increased by 57.8%, root mean square (RMS) increased by 63.5%.