The utility model relates to a two cross arm beam electric power tower prevent bird insulating sheath, including fixing the annular metallic hoop on the two cross arm beam top power pole body, the annular metallic hoop is fixed the suitable for reading of coniform plastics umbrella face on the power pole body through connecting bolt, and on the under shed edge of the coniform plastics umbrella face oriented outer open and flat collar limit of a system, the collar limit is edge -fixed on two cross arm beam with the under shed of coniform plastics umbrella face through encircling the limit bolt, and the installation splint of coniform plastics umbrella face on with the power pole body are contained in the below of coniform plastics umbrella face, in addition, are the under shed inboard and the contained angle between the level of coniform plastics umbrella face 30 degrees 35 between the degree. The utility model discloses prevent birds nest on the shaft tower, solved the problem of birds nests on the distribution shaft tower from the source to solve the failure interruption that distribution overhead line caused because of the bird's nest, constantly promote and join in marriage net safety and service reliability.