Since the operating speed and tracking path of intelligent tractors are constantly changing, the model predictive control based on fixed parameters cannot achieve ideal results. This paper proposes a variable universe fuzzy adaptive weight MPC tracking control algorithm considering automatic steering system. Firstly, the tractor dynamics model, tire mechanics model and automatic steering system model are constructed. Secondly, a linear tracking error model is constructed based on the tractor dynamics model and the automatic steering system model. Again, a path-following control algorithm based on MPC is designed. Then, in order to improve the control precision and self-adaptability of MPC, a fuzzy self-adaptive weight regulator with variable universe is designed. Finally, the co-simulation of pear-shaped and semi-circular operating conditions is designed. The simulation results show that the model predictive controller considering the automatic steering system solves the problem of excessive tracking error caused by the delay, overshoot and oscillation of the automatic steering system in the tracking process; the variable domain fuzzy adaptive weight regulator realizes the adaptive weight Adjustment, so that the tracking control effect can meet the operation requirements under different operating speeds, and the speed robustness of the tracking control is improved.