Taking the excavator as the research object,the mathematical models of kinematics and dynamics of the excavator working device were established.The motion trajectory was discretized by using the 5-degree polynomial interpolation method.The discrete motion trajectory program was compiled using MATLAB and its calculation results were compared with the ADAMS simulation results,the dynamics model parameters were determined.The Simulink and ADAMS joint simulation model based on the dynamics model was established.In the dynamic control,the PD control method was used,and the trajectory planning joint simulation was conducted and tested.The results show that the motion trajectory control method based on the dynamic model can effectively avoid the sudden change of the starting and ending positions and the output force of the hydraulic cylinder.With the PD control method in dynamic control,the obtained convergence trend is nearly 50% higher than that of the unoptimized one.The output force of the hydraulic cylinder changes stably with an error of about 5%,which improves the control accuracy of the automatic excavation motion trajectory.