The high-speed ceramic electric spindle is applied in high-speed NC machine tools. Each surface processing accuracy requirement of high-speed ceramic electric spindle is high. The inner hole surface roughness is the key factor which affects its high-speed stability and moving accuracy. This paper focuses on the research of the relationship between inner hole and grinding wheel granularity and grinding wheel linear velocity and transverse feeding and grinding camber ratio through the experiment of diamond wheel grinding the inner hole of ceramic spindle. The optimal grinding parameter combination of ceramic spindle inner hole grinding is obtained. The surface roughness of ceramic spindle inner hole reaches 0.21μm, through the analysis of orthogonal test. The results can completely satisfy the ceramic spindle high-speed operation requirements and enhance the ability of corrosion resistance and fatigue damage resistance. It then improves the whole work performance, reliability and life of ceramic spindle.