The invention provides an automatic underwater acoustic target azimuth tracking method for preventing tracking deflection. The method comprises the steps of (1), acquiring an underwater acoustic target azimuth history chart; (2), performing singular value decomposition on the acquired underwater acoustic target azimuth history chart, and using a mapping space which corresponds with a highest singular value that is obtained through decomposition as a first sub-space; (3), acquiring a main atlas P of the underwater acoustic target azimuth information based on information which is mapped to the first sub-space; and (4), performing automatic tracking of the underwater acoustic target based on the track on the main atlas P of the underwater acoustic target azimuth information. The tracking method according to the invention can effectively prevent tracking deflection in tracking the underwater acoustic signal and furthermore improves tracking accuracy.