In view of problem that global optimal path was difficult to determine due to disturbance of obstacle interval in process of path planning for coal mine search and rescue robot, optimal path planning algorithm for coal mine search and rescue robot based on gradient-coordinate rotation method was proposed. The robot first moves according to gradient-coordinate rotation method, then performs local path optimization according to existing motion path, and makes feasibility judgment on the planned local optimal path until there is no obstacle interval in the path. The simulation results show that the algorithm can make the coal mine search and rescue robot accurately plan the global optimal path from starting point to target point under the premise of avoiding obstacles, so as to improve rationality and efficiency of robot motion path planning.