The utility model discloses a lightning arrester installation bracket which comprises a bridge-shaped iron plate, a connecting plate, a base plate, support plates and a V-shaped bolt. The bridge-shaped iron plate is provided with a center hole and a curved hole. Connecting holes are arranged on an upper left corner and an upper right corner of the bridge-shaped iron plate. Two clamp holes are arranged on the lower end of the bridge-shaped iron plate, wherein the bottom of each clamp hole is open. One screw of the V-shaped bolt is long, while the other screw of the V-shaped bolt is short. The V-shaped bolt is clamped on a ground wire cross arm, and two screws respectively pass through the connecting holes and the clamp holes on the bridge-shaped iron plate. The connecting plate and the bridge-shaped iron plate are connected by the bolt through the center hole and the curved hole. The upper end of the connecting plate extends out of the bridge-shaped iron plate. Two support plates are welded on the connecting plate. The support plates are vertically arranged. The base plate is welded on the top ends of two support plates, and at the same time the base plate and the connecting plate are welded. According to the utility model, the lightning arrester installation bracket has the advantages of simple structure, strong bearing capacity and being durable, and can adapt to ground wire cross arms of different sizes; successful installation can be realized once; and the work efficiency is significantly improved.