Abstract: Aiming at the problem of precise trajectory control of excavator, the dynamics model for excavator is built, and the automatic call of excavator dynamics module, PD control system module and PD parameter input module is built under the Simulink simulation environment. The PD weight parameters are obtained through the PSO optimal search. The excavator dynamics model is defined in the PSO program, and a closed-loop fast adaptive tuning joint simulation is carried out under the dynamic control. The simulation results show that the excavator PD controller based on the particle swarm optimization algorithm can achieve the desired trajectory control compared with the traditional trial and error method, and both of them are close to the theoretical value; but the excavator PD controller based on the particle swarm optimization algorithm can quickly adapt to the adjustment, and it converges by 75% compared with the 200-5 combination of K_P and K_V in the trial and error method in the initial process of the excavation trajectory, which reduces the steady-state error of the system. It greatly improves the stability and accuracy of hydraulic excavator.