The utility model relates to a transformer protective earthing device, and belongs to a power distribution equipment earthing device. The transformer protective earthing device comprises a grounding grid, a ground stud is disposed between the grounding grid and a transformer, one end of the ground stud is inserted into the ground while the other end is fixed on a wiring angle iron which is disposed above the ground and perpendicular to the ground stud, the two ends of the wiring angle iron are provided with a first connection hole and a second connection hole respectively, the wiring angle iron is connected with a grounding grid lead of the grounding grid through the first connection hole and connected with a grounding lead of the transformer through the second connection hole, and a limiting gib parallel with the wiring angle iron is fixed in the middle of the ground stud and is buried under the ground. The transformer protective earthing device provided by the utility model can help to ensure safe operation of the equipment, remove potential safety hazards during measurement, save operating time and raise working efficiency.