Abstract: In order to enhance the efficiency of tunnel support in coal mines, a study focused on the six-degree-of-freedom drill anchor robot manipulator arm and proposed an optimal trajectory planning method based on an improved grey wolf optimization algorithm. Firstly, the kinematic model of the manipulator arm was established using the D-H parameter method. Monte Carlo method was utilized for workspace analysis of the manipulator arm, and MATLAB software was employed for simulation verification; Secondly, joint-space trajectory of the manipulator arm was planned using piecewise polynomial interpolation; Finally, an improved grey wolf optimization algorithm was proposed and its performance tested for time optimization of the manipulator arm based on trajectory planning. The results show that the drill-anchoring robot manipulator meets the requirements for coal mine roadway anchoring operations; the 3-5-3 piecewise polynomial interpolation method provides smoother operation of the manipulator; and the time required for the manipulator to reach predefined trajectory points under constraint conditions is reduced by 30.40 % to 50.28 %, outperforming traditional trajectory planning methods.