Rolling forming technology can effectively improve the utilization rate of metal materials and improve the fatigue strength of gears. In this paper, the rolling forming technology of straight cylindrical gear is studied, the tooth surface equation is derived, and the calculation of tooth surface points is realized. The rolling forming process of straight cylindrical gear is simulated by using DEFORM software, and the changes of equal effect force field, equivalent strain field and rolling force are analyzed. The formation mechanism of lug defects in rolling is explored, and the action law of friction coefficient on lug is studied, so that the optimization of friction coefficient oriented to lug control is realized, which provides a theory for the rolling forming of straight cylindrical gear.