Taking the 8-DOF multijoint rock drilling rig mechanical arm as the research object,based on the introduction of the doubletriangular support structure of the rock drilling rig,the mathematical modeling of the independent doubletriangular support hydraulic position servo system was built.The MATLAB software was used to draw its Bode diagram to get the dynamic characteristics of the system.The PID parameters were set by using Z-N tuning method,and the system was simulated in Simulink.The results show that the stability,response speed and antiinterference ability of the control system using PID controller meet the actual use requirements.