The utility model relates to an outdoor transformer station maintenance device comprising a first vertical surface, a second vertical surface opposite to the first vertical surface, and a detachable guardrail used for connecting the first vertical surface and the second vertical surface, and the first vertical surface and the second vertical surface are parallel to each other. Photoelectric generation devices are uniformly arranged on the inner side of the first vertical surface; photoelectric receiving devices are uniformly arranged on the inner side of the second vertical surface; the photoelectric generating devices and the photoelectric receiving devices are in one-to-one correspondence; light emitted by the photoelectric generation device is horizontally emitted to the photoelectric receiving device, a sound alarm and a controller are arranged on the outer side of the second vertical face, the sound alarm and the photoelectric receiving device are connected with the controller through wires, and the first vertical face and the second vertical face are both metal iron-containing vertical faces. The utility model has the advantages of simple structure, safety, reliability and convenience in disassembly, and can be formed by simple metal plates.