Objective To improve surface quality and work efficiency of the safety valve seat and disc. Methods A sand paper was used as grinding medium, and the effects of the fineness of the sand paper, the grinding pressure, rotating speed of grinding machine, grinding time, and grinding path on material removal rate and surface roughness of the valve seat and disc were studied. It was supposed to obtain optimal process parameters by the orthogonal experiment analysis and comprehensive consideration on the influence of various process parameters on the material removal rate and surface roughness. Results After selecting optimal parameters of key factors in grinding process, the material removal rate reached 26. 2 μm/ min, the surface roughness was reduced to 0. 028 μm, and the lapping repair efficiency was improved to 90% . Conclusion The optimal parameters were Sandpaper fineness 1500 mesh, the grinding pressure 30 N, grinding machine speed 50 r/ min, milling time 20 min, figure 8 grinding path.