Abstract: To meet the processing requirements of the complex-shaped surface of reactor coolant pump seal ring, a piece of polishing equipment with four-axis linkage and polishing load monitoring function has been designed. The layout of the polishing equipment is horizontal, and its essential parts are designed and analyzed. The control system of the equipment operates based on the "embedded motion controller-driver-motor" scheme. In the scheme, linear axis movement is achieved by motors driving the ball screw mechanism, and a force sensor can monitor the polishing load in real time. Typical seal ring polishing tests are conducted on the polishing equipment. After 160 min polishing under an average load of 26 N, the roughness Ra of the seal ring decreases from 282 nm to 5.9 nm, meeting the polishing processing requirements of the sealing ring. It offers both equipment and process for high-quality and high-efficiency processing of reactor coolant pump seal ring, and helps to improve the technical level of high-precision manufacturing of seal ring.