The invention belongs to the technical field of lightning protection and grounding devices for overhead power lines. The technical problem to be solved is that the connection of the grounding device of the power line tower depends on the bulky generator, welding machine, waste of resources and danger. The technical scheme adopted is that one end of the connecting inner pipe is inserted into the tapered blind hole on the threaded part of the connecting block, the other end is inserted into the tapered through hole of the connecting outer pipe, the connecting outer pipe is connected with the threaded part on the connecting block through the internal thread, and the annular boss on the connecting outer pipe is matched with the step on the step part of the connecting block; The diameter of oneend of the connecting inner tube inserted into the threaded portion of the connecting block is larger than the diameter of the small diameter end of the tapered blind hole on the threaded portion ofthe connecting block; The diameter of one end of the connecting inner tube inserted into the connecting outer tube is larger than the diameter of the small diameter end of the tapered through hole onthe connecting outer tube; The invention is used for a quick and simple grounding device for connecting electric power line towers.