Abstract: In order to improve the middle and deep seismic imaging in the Panyu 4 Depression of the Pearl River Mouth Basin, the wide azimuth seismic exploration test by twin-boat towline was carried out, and 1 680 folds of full coverage seismic data acquired. According to an azimuth width of 15 degrees, 24 azimuth volumes are created and processed, and the data of different azimuth widths and orthogonal dual azimuth data are superimposed respectively. The results of different azimuth widths and different folds are collected and analyzed. It is concluded that the seismic imaging effect is significantly improved with the increase in azimuth width and folds; under the same folds, the dominant imaging azimuth imaging effect is better; and the imaging effect of orthogonal dual azimuth is between the two directions, which has no advantage with the imaging effect of dominant imaging azimuth. Therefore, the most effective way to improve the effect of middle and deep seismic imaging is to increase the number of folds in target dominant imaging azimuth.