Box type cross arm for electric transmission line steel pipe pole

The utility model discloses a box type cross arm for an electric transmission line steel pipe pole. The box type cross arm comprises a lower cover plate and two side stand plates. The two side stand plates are welded to two opposite side edges of the lower cover plate respectively, and the two side stand plates are parallel to each other and perpendicular to the lower cover plate. The box type cross arm further comprises an upper cover plate welded to the upper edges of the two side stand plates. The side stand plates comprise the inner side stand plate arranged on a pole and the outer side stand plate away from the pole, the inner side stand plate and the outer side stand plate are welded together, the thickness of the outer side stand plate is smaller than that of the inner side stand plate, and a box type structure is formed by the side stand plates, the upper cover plate and the lower cover plate. A wire hanging plate is arranged on the upper cover plate. According to the box type cross arm for the electric transmission line steel pipe pole, steel is saved, and workers can lay the cross arm and maintain the line conveniently.