In view of the blindness and contingency of the trial cutting method in traditional processing of spiral bevel gears, this paper proposes a processing adjustment method of designing grinding wheel section according to the curvature of the tooth surface. Firstly, the spiral bevel gear is simulated by CATIA to build a high-precision cutting model. In ABAQUS, the finite element analysis of the cutting model is carried out, and the contact spots are extracted. Then, according to the analysis results of the cutting model, the curvature and node offset of the tooth surface are calculated for contact area adjustment. Finally, the grinding wheel section is designed according to the cutter section and the offset of the tooth surface, which is called in the virtual grinding. The analysis results show that the contact performance and transmission performance of the gear after curvature adjustment are greatly improved, which indicates that the tooth surface curvature adjustment is realized by adding the grinding process, and it is in line with the actual process flow. It provides a new research method for transmission error optimization and contact area correction of spiral bevel gear system.