Abstract: Proportional-integral-derivative（PID） control algorithm is widely used in the angle control system of tea garden tractor, but the PID controller brings a lot of parameters setting and hysteresis, which can inevitably reduce the control accuracy and control efficiency. To solve the problem, a tea garden tractor angle controller based on the grey wolf optimization algorithm（GWOA） was proposed. A simplified mathematical model for electric power steering（EPS） system of tea garden tractor was established, and a PID-based motor current-steering wheel angle double closed-loop control strategy was adopted. The GWOA was designed to optimize the parameters of the traditional PID controller, and the PID angle controller based on GWOA was constructed. CARSIM and MATLAB were used to simulate the tractor operation in real time, and the proposed tea garden tractor angle controller algorithm based on GWOA was verified. The results show that the total current harmonic distortion（THD） of the traditional PID controller is 11.46%, and the THD of the particle swarm optimization（PSO）PID controller is 8.12%. The THD of the proposed GWOA-PID controller is 6.28%, which reduces the current harmonics by 45.2%.