Aiming at the problem that precision of GT35 dynamic motor shaft was difficult to be guaranteed,and its low efficiency and high cost,the research on precision grinding process of motor shaft was carried out.The influencing rules of different grinding wheel parameters on workpiece shape accuracy,surface quality,specific grinding energy and so on were studied by comparing different diamond grinding wheels with different binders,different particle size and concentration,and the grinding wheel with superhard abrasives was designed.Through orthogonal test,the optimal process parameters which influenced the axis precision grinding surface roughness,roundness,cylindrical degree were determined.By making use of optimal grinding parameters to 20 motor shaft grinding,the validation test was carried out.The result shows that the best workpiece with roundness 0.11 μm,cylinder 0.34 μm and roughness Ra 0.041 μm is obtained when the workpiece speed is 304 r/min,feed speed is 0.003 m/min and feed rate is 1 μm.