The utility model provides a grading ring for a single connection V-shaped composite insulator chain for 500 kV line and 5000m altitude. The grading ring comprises a ring body and a support in welding connection with the ring body. The grading ring is characterized in that the ring body is a round plane with an end equipped with an opening, the diameter of the ring body is 80mm and the diameter of the support is 36mm. The radius of the round plane of the ring body is 450mm. The distance of two end points of the opening part is 100mm. The ring body and the support are made of aluminum. The grading ring is suitable for a single connection V-shaped composite insulator chain in a 500 kV line and at an altitude of 5000m, and ensures safe operation of a power transmission line in high-altitude regions. Voltage distribution around fittings is improved effectively and visible coronas, noise and radio interference are reduced. In addition, the size of the grading ring support is increased, the stress structure is optimized, and working stability of the grading ring under bad conditions is ensured.