The invention belongs to the technical field of oil and gas field exploration, and discloses a method for extracting azimuth information of offshore narrow azimuth seismic data. By means of azimuth trace gather input, azimuth division angle calculation, azimuth trace gather division, data regularization, noise suppression, sub-azimuth superimposed data processing, amplitude attribute extraction and amplitude attribute subtraction, difference results of different azimuth data are obtained, the azimuth information extraction of narrow azimuth (the aspect ratio is less than 0.5), especially offshore towline collection seismic data is realize, and the azimuth information of the narrow azimuth seismic data is fully exploited. According to the method disclosed by the invention, the conventionalmethod of dividing azimuth angles according to a unified standard is improved to a differential division method based on one-sided elements, thereby avoiding the phenomenon that the coverage times ofone azimuth angle are extremely high and the coverage times of one azimuth angle are extremely low caused by the conventional division of the azimuth angles; and the quality of the azimuth angle tracegather of narrow azimuth data division is further improved by data regularization and noise suppression, and a technical foundation is laid for the extraction and use of the azimuth information.