This paper presents a novel approach to address the challenge of high difficulty and low efficiency of substation inspection. Specifically， the proposed approach is a global path planning method for substation inspection robots based on ant colony algorithm. The key idea behind this approach is to simulate the foraging behavior of ants using the ant colony algorithm， and then use continuous iterative optimization to determine the optimal path for the inspection robots. To evaluate the effectiveness of the proposed method， this paper compared it with the traditional path planning method based on Dijkstra algorithm. The results demonstrate that our approach is characterized by higher search efficiency and better solution， thereby making it a promising alternative for substation inspection.