The utility model relates to an electric power system machinery discloses a transformer dysmorphism earthing device, and this earthing device includes earthed busbar, and earthed busbar has seted up the middle part through -hole, still includes the contact plate, and contact plate one side the edge is fixed with the insulating rod, is close to near insulating rod and is fixed with on the contact plate lower surface to meet ground wire terminal, connects ground wire terminal to connect the earth connection, and pervious screw has been seted up to the contact plate middle part, and the bolt that has with screw cooperation spiro union passes at the bolt the through -hole is fixed earthed busbar with the screw cooperation spiro union on the contact plate with the contact plate, the area of contact that the device can the satisfying criteria requires ensures normal drainage to ensure the transformer and normally work, avoid unnecessary personal damage accident to take place, improve the security that the transformer used.