Pressure gradient vector hydrophones are composed of multiple pairs of independent scalar hydrophones. However, the amplitude and phase errors between the scalar hydrophones can cause the distorted pressure difference directivity and degrade the direction-finding accuracy of underwater targets. To address this issue, an active rotational correction method using the inherent dipole directivity is proposed to correct the intrinsic amplitude and phase errors of pressuregradient vector hydrophone hardware system, which does not require the accurate position of auxiliary sound source. The vector hydrophone is rotated 360° on a precision turntable. Meanwhile a scalar hydrophone located off the rotation axis is selected as the reference, and the amplitude scaling and time-domain shifting optimization are applied to the signals of other hydrophones until the pressure difference directivity curves are corrected to their ideal shapes, thereby compensating for the amplitude and phase errors. Amplitude/phase error correction and sound source localization experiments are conducted in an anechoic tank using a laboratory-developed three-dimensional pressure-gradient vector hydrophone. The results show that the corrected pressure difference directivity curves of vector hydrophone closely approximate the ideal shapes. Compared to the results before correction, the number of test points with azimuth errors below 5° increases by 10.6%, and the number of test points with elevation errors below 10° increases by 92.9% in rotating hydrophone tests; meanwhile the number of test points with azimuth errors below 5° increases by 46.3% and the number of test points with elevation errors below 10° increases by 42.6% in moving sound source tests. Experimental results verify that the proposed method effectively corrects amplitude and phase errors of the pressure-gradient vector hydrophone, which significantly improves the accuracy of underwater target localization. This method reduces the difficulty and cost of amplitude and phase error correction, making it valuable for practical applications.