A line loss positioning device for a low-voltage overhead line mainly comprises a plurality of mutual inductors, a meter, a wireless data transmitting terminal and a carrier wave acquirer. The mutual inductors are electrically connected with one another. The line loss positioning device is characterized in that each mutual inductor consists of a body and an end cap which are hinged to each other; the meter comprises a mainframe, an operating shell, a liquid crystal display surface device and two rows of binding posts; the mainframe is an MCU (microprogrammed control unit) processing control module and is arranged in the operating shell; the liquid crystal display surface device is fixed on an upper end surface of the operating shell; the two rows of binding posts are respectively arranged on the upper side and the lower side of the upper end surface of the operating shell symmetrically; the binding posts on the upper side and the lower side are respectively connected with corresponding interfaces of the mainframe in the operating shell; the mutual inductors are connected with the corresponding row of binding posts of the meter; the other row of binding posts of the meter are connected with the wireless data transmitting terminal; data are transmitted through an RS-485 communication protocol; and data of the wireless data transmitting terminal and data of the carrier acquirer are transmitted through radio wave.