The invention relates to the technical field of processing of cross arms, in particular to a cooling device for the welding position of a cross arm. The cooling device is used for rapidly drying the cross arm obtained through welding and comprises a rack, a first support, second supports, an air inlet pipe, exhaust pipes and a fan. Two parallel sliding grooves are formed in the upper portion of the rack. The first support is adjustably arranged on the left sides of the two sliding grooves, the lower portion of the first support is connected with the air inlet pipe, and the other end of the air inlet pipe is connected with the fan at the bottom of the rack. The upper side wall, the lower side wall, the left side wall and the right side wall of the first support are communicated with the exhaust pipes respectively, an air nozzle is arranged at the free end of each exhaust pipe, and the air nozzles surround the cross arm to be cooled. The right sides of the two sliding grooves are each adjustably provided with one corresponding second support, a vertical lead screw is arranged on the upper portion of each second support in a rotating manner, and lead screw nuts are arranged at the bottoms of the lead screws. The cross arm can be rapidly cooled, so that the needs for rapid producing and processing are met, and production efficiency is improved.