Submarine cable routing and fault point positioning method

The invention provides a submarine cable routing and fault point positioning method. A submarine cable sound wave receiving device is adopted to receive sound waves emitted by two sound sources with known coordinates, submarine cable routing positioning is achieved through the time difference between two sound production times of the two sound sources received at a single point after the sound waves are continuously received twice, and then pre-positioning is conducted on a fault point through the distributed optical fiber sound wave sensing technology. According to the relative position relation between two sound sources and a fault point with the sound wave receiving device as the reference, the smaller the time difference of sound signals sent by the two sound sources and the fault point received by the sound wave receiving device is, the closer the distance between the two sound sources and the fault point is, so that the two sound sources approach the fault point along the route direction of the submarin