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.