The hardness of driving gear thread induced tempering can be controlled below 45hrc, and the local hardness at R can reach below 48hrc. The problems of induction tempering are as follows: the local heating temperature of the screw thread is high, the heat penetration depth is about 6 mm, and the driving gear has secondary martensite locally after medium temperature tempering, which is easy to fracture. Therefore, the heating temperature is controlled at 650-700c, and the thread heating temperature is uniform and the heat penetration depth is uniform. The comprehensive process of thread induction tempering has the advantages of low production cost, low labor intensity, high productivity, no environmental pollution and stable product quality.