Abstract: Passivation of cutting edge can eliminate the microscopic defects, and effectively improve the cutting edge strength, tool life and cutting stability. However, at present, the domestic attention to the passivation of hob edge is low, which restricts the improvement of tool quality. In this paper, the passivation method of hob edge, passivation medium and passivation time, the theoretical calculation of passivation fillet and so on are studied. Through the hob passivation tests and hob cutting tests, it is proved that the blade passivation can effectively improve the durability and life of hob. It provides a basis for the research of hob passivation.