The invention discloses an outdoor transformer protective cover, includes a cuboid cover, at that bottom of the cuboid cover, at that bottom two side of the cuboid cover body, mount plates are respectively arranged, the mounting plate is provided with bolt fixing holes, a cushion plate is fixedly arrange on that inner side wall and the top wall of the cuboid cover, a longitudinal heat dissipationgroove is respectively arrange on that front end surface and the rear end surface of the cuboid cover body, a dust-proof net is arranged on that front face and the rear face of the rectangular body cover, and insulate material is sprayed on the outer wall of the rectangular body cover. The invention has novel structure design, excellent anti-pressure buff effect, good ventilation, dust-proof, insulation effect and effective protection of the internal transformer.