The invention belongs to the technical field of underwater acoustic positioning, and relates to a submarine flight node positioning method. According to the method, four underwater acoustic beacons with known and fixed positions are used for simultaneously transmitting underwater acoustic signals according to a fixed period, and clock synchronization is realized between the underwater acoustic beacons and a submarine flight node; the submarine flight node receives the underwater acoustic signals, records the arrival time of the signal, and calculates the transmission time of the underwater acoustic signals; when the submarine flight node does not receive the underwater acoustic signals, inertial navigation is carried out through a low-cost inertial measurement unit carried by the submarineflight node; after receiving the underwater acoustic signals, the submarine flight node performs single beacon positioning position calibration through extended Kalman filtering; and after a plurality of underwater acoustic signals transmitted at the same moment are received, the submarine flight node performs long baseline positioning position calibration through a least square method. By fusingunderwater long baseline positioning and single beacon positioning, the defects that long baseline positioning is poor in real-time performance and single beacon positioning is low in precision are overcome, and the requirement for high-precision real-time positioning of submarine flight nodes is met.