The utility model relates to a live -wire operation tool especially relates to a special drainage line of arc extinction switch, it includes drainage line, arc extinction switch, connects female head and connect public head, fixation nut is installed to arc extinction switch side wall bottom, the lateral wall upper portion of connecting public head is equipped with the side screw rod that matches in the screw in fixation nut, the lower part of connecting public head is equipped with the external screw thread, and the upper portion of connecting female head is equipped with the internal thread, connects public head through the fixed suit of external screw thread and the interlock of internal screw thread matching in that to be connected mother overhead, the bottom of connecting female head is continuous with the one end of drainage line. Owing to implement above -mentioned technical scheme, this application is connected public head and is installed on fixation nut through the screw rod that inclines through installation fixation nut bottom the arc extinction switch, connects female head and links to each other with the drainage line, through connecting mother's head and connecting public first screwed connection cooperation, can realize drainage line and the reliable of arc extinction switch and be connected that operation process is simple, reduces intensity of labour.