The invention discloses an overhead line repairing device comprising a walking mechanism and a wire supporting mechanism arranged on the walking mechanism. The walking mechanism comprises a left walking bracket and a right walking bracket. The upper part of the left walking bracket is provided with a rightward-extending crossbeam. A first dovetail groove is disposed on the bottom surface of the crossbeam. The top of the right walking bracket is provided with a first dovetail joint which cooperates with the first dovetail groove. The wire supporting mechanism comprises a pulley frame, and a driving pulley and a driven pulley which are arranged inside the pulley frame. A power platform is disposed on the lower part of the front side of the pulley frame and is provided with a driving motor. The output shaft of the driving motor is connected with the rotating shaft of the driving pulley through a flange. A control platform is arranged on the lower part of the rear side of the pulley frame and is provided with a CPU module. The overhead line repairing device can be used for repairing a broken wire in an overhead line, can be adjusted in position on the overhead line as required, improves repair efficiency, prevents the phenomena of sliding displacement and dropping during the operation, and improves reliability.