Taking the generation mechanism of helical gear involute as the starting point, and according to the structural characteristics of helical gear, the relationship between the basic parameters of helical gear end face and normal face is analyzed. Taking this as the theoretical background, the involute equation of helical gear is obtained, and the equation of tooth root transition curve is established.

According to the structural characteristics of the helical gear, the parametric feature model of the helical gear is established. Through the pro parametric modeling tool, the driving relationship between the basic parameters of the helical gear and the dimensions of the helical gear is defined. By changing the basic parameters of the helical gear, the parametric feature model of the helical gear can be regenerated to facilitate the subsequent establishment of the helical gear model, At the same time, it also provides a model basis for subsequent finite element analysis.