The invention provides an earthing ring. A telescopic insulating sheath is arranged on an insulating sheath at one side of an earthing section of the existing earthing ring; the other end of the telescopic insulating sheath is connected with an insulating ring; the telescopic insulating sheath is shrunk to enable the earthing section to be exposed, and the telescopic insulating sheath is stretchedto coat the earthing section; and a buckling device is arranged on the insulating sheath at the other side of the earthing section for controlling the telescopic insulating sheath to be switched between a shrinking state and a stretching state, and the buckling device is made of an insulating material. According to the earthing ring, through arranging the buckling device and the telescopic insulating sheath on the earthing ring, the problems that single phase or interphase short circuit fault is likely to happen as the grounding wire hanging part of the existing electricity testing earthing ring is in an exposed or non-insulating state for a long time can be solved.