The invention relates to a transmission line OPGW lightning locating and monitoring device. An OPGW optical cable communicates A and B substation communication machine rooms. A laser light source is connected with an optical signal conditioner. The optical signal conditioner is connected with one optical fiber at the A substation end of the OPGW optical cable through a metal sleeve optical fiber connector and an FC single-mode optical fiber jumper. An optical fiber corresponding to the B substation end of the OPGW optical cable is connected with the other optical fiber in the same core. The other optical fiber corresponding to the A substation end of the OPGW optical cable is connected with a filter. The filter is connected with an electric signal conditioner. An electric signal output by the electric signal conditioner is connected with an acquisition card. The acquisition card is assembled in a bus slot of an industrial personal computer. A power panel supplies power to all the active devices. The device of the invention is mounted in a substation communication machine room, a line OPGW optical fiber is used as a lightning signal sensor and processes signals after accessed to the device, the device controls the data acquisition card to acquire data in real time, and the acquired data is analyzed and processed, so that the lightning waveform can be extracted, and the precise location where a transmission line is struck by lightning can be worked out.