The mathematical model of the quenching process of straight tooth cylindrical gear was established. The quenching temperature field was numerically simulated by Ansys software. Temperature field and stress field of the gear in the quenching process with different initial water temperatures were analyzed. The results show that in the quenching process, the tooth core temperature of the cylindrical gear is the highest, and tooth top temperature is lowest. There is a big difference between the tooth crown and ...