The invention discloses an electric transmission line strain clamp maintenance tool, and relates to the technical field of electricity maintenance tools. The electric transmission line strain clamp maintenance tool comprises an operation rod, a U-shaped clamp body and a clamping mechanism. The clamping mechanism comprises a pushing clamping plate, a screw and a force application ring, the pushing clamping plate is arranged inside the U-shaped clamp body, and the force application ring deviates from the screw and is connected with the screw through a rotating arm; a threaded hole is formed in the first side plate of the U-shaped clamp body and matched with the screw, and the end of the screw is fixedly connected with the pushing clamping plate; the top end of the operation rod is provided with a connecting clamping head matched with the middle of the U-shaped clamp body, and the side face of the top of the operation rod is further provided with a force application hook matched with the force application ring. The U-shaped clamp body is lifted to an electric transmission line strain clamp through the operation rod, a portion needing to be fastened is clamped, the force application ring is rotated by means of the force application hook on the top of the operation rod, the pushing clamping plate is driven by the screw to move transversely, the loose portion is clamped, and the problem that a lap plate is excessively hot and loose is solved safely and reliably.