Underwater positioning method of underwater vehicle capable of separating child from mother

The invention discloses an underwater positioning method of an underwater vehicle capable of separating a primary aircraft from a secondary aircraft, and belongs to the technical field of underwater vehicles. When a primary aircraft and a secondary aircraft are combined to operate on the water surface, the underwater vehicle is positioned through a primary aircraft positioning navigation system of the primary aircraft; when the combined body of the mother aircraft and the son aircraft dives to underwater operation, the underwater vehicle performs dual-system calibration and positioning through the mother aircraft positioning and navigation system and the son aircraft positioning and navigation system; when the master machine and the slave machine are separated for operation, the optical fiber is released and tensioned, the master machine is positioned through the master machine positioning navigation system, and the slave machine is positioned through the master machine positioning navigation system, the slav