Abstract: This paper designs a trajectory tracking control algorithm based on pre-targeting pure tracking model and fuzzy control, and an automatic steering control system based on hydraulic system and PID algorithm. In order to test the effect of the trajectory tracking control algorithm and the automatic steering control system, the agricultural machinery trajectory tracking and steering control experiments were carried out using the wheeled robot for field operation as the test platform. The results show that: in the trajectory tracking test, when the vehicle speed is 0.6m/s, the maximum lateral deviation is 0.07m, and the average lateral deviation is about 0.05m; in the steering control test, the steering angle response time does not exceed 1.5s, and the overshoot is less than 5%.