The utility model relates to a transmission line electroscope specifically is 660KV direct current transmission circuit electroscope, solves the problem that lacks 660KV direct current transmission circuit electroscope at present, and the scheme is: including work portion, insulating rope and operation hand wheel, work portion personally experiences sth. Part of the body for the cavity that the end was equipped with the conductive contact piece, and the work portion other end even has insulating rope, and the insulating winding of restricting on the operation hand wheel, is equipped with the high -pressure inverter circuit who is connected with the conductive contact piece in the work portion, and high -pressure inverter circuit's output has connected gradually bleeder circuit, filter circuit, multi resonant oscillation circuit and acousto -optic warning circuit. The advantage: 1, but whether the direct detection 660KV direct current transmission circuit is electrified, compensaties the not enough of present scarce measuring equipment, 2, easy and simple to handle, safety, 3, simple structure conveniently carries, 4, but the self -checking, the convenient maintenance.