To improve the accuracy of the trajectory tracking of hydraulic excavator working device, Lagrange dynamics model of hydraulic excavator working device was established.Because the hydraulic excavator working device had highly nonlinear, time lay, parameter uncertainty, sliding mode algorithm based on the low pass filter was proposed.The simulation results showed that the sliding mode control method was based on the low pass filter, which effectively eliminate chattering phenomenon, and improved the fast tracking performance and dynamic response performance of the system, and had a stronger robustness to parameter uncertainties.

Through the improvement of small excavator hydraulic system, by using AMESim software and establishing a simulation model of excavator boom hydraulic system, the influence of PID controller parameters on the system dynamic performance was analyzed. At the same time, its dynamic performance was simulated and analyzed. The results show that the global optimal solution of PID parameters improves the performance of excavator boom hydraulic system and obtains good effect, which offers references for the frequency response speed and stability of the system.