The inversion of Scholte wave dispersion curves is one of the most important methods employed in the detection of marine sedimentary structures. The measurement methods of Scholte wave dispersion are primarily developed from terrestrial geophysical exploration technologies. Unlike terrestrial seismic source excitation methods, marine exploration typically uses air guns to generate seismic waves in seawater, which will result in strongly dispersed Guided-P waves. We found that the Guided-P waves will truncate the higher-mode dispersive Scholte waves at their lower cutoff frequency. However, a simple individual preprocess of suppressing Guided-P procedure (SGP) before extracting dispersion curves can significantly increase the frequency band and image the full dispersive modes of Scholte waves. The wider frequency band and higher-mode Scholte wave dispersion curves can effectively improve the constraints on the submarine shear wave velocity structure. Based on this, we highly recommend adding this simple step to Scholte wave dispersion imaging.