The value of the gear module is m = 1, the number of teeth of the driving gear is Z = 23, the pressure Angle is luang = 20, the spiral Angle of the gear is sun = 12, and the gear rack should be determined according to the value of the steering wheel. The rotating speed of the gear n = 10R/min, the gear transmission torque 25nm, steering device works 8 hours a day, the service life is not less than 5 years, the active pinion gear selection 40Cr, material manufacturing and carburizing quenching, and the rack is usually used 40Cr steel or 41Cr4 manufacturing and high-frequency quenching, the surface hardness should be in 56hrc above. To reduce weight, 40Cr steel was used.