Submarine cable secondary positioning method based on integrated positioning of acoustic long baseline and ultrashort baseline

The invention discloses a submarine cable secondary positioning method in geophysical exploration, which comprises the steps of: fixing a transponder on a submarine cable to be tested, installing an underwater acoustic transducer on a survey vessel, installing two transducers in the underwater acoustic transducer, wherein the two transducers form an ultrashort baseline array, wherein one transducer is used as a receiving and transmitting combined transducer and the other one is only used as a receiving transducer; sending a call signal by one transducer, recognizing the call signal and sending a response signal by the transponder, receiving the response signal and processing and figuring out geodetic coordinates of the transponder to obtain a left position and a right position of the transponder in the survey vessel, and determining an accurate position of the transponder and the final geodetic coordinates. The invention overcomes the problem on positioning a mirror image with the long baseline, improves the positioning accuracy and the positioning reliability, realizes the randomness of a positioning ship sailing at two sides of a survey line, is convenient for marine positioning construction, increases the construction efficiency by one time and has a positioning accuracy superior to 1m.