The invention discloses a differential structure-based interferometric optical fiber hydrophone probe. According to the differential structure-based interferometric optical fiber hydrophone probe, a three-layer thin-walled cylinder nested hollow free water overflow structure is adopted; the three-layer thin-walled cylinder nested hollow free water overflow structure includes an inner optical fiberring supporting thin-walled cylinder, an outer optical fiber ring supporting thin-walled cylinder and a protective housing which are distributed sequentially from inside to outside; sound transmission holes are formed in the inner optical fiber ring supporting thin-walled cylinder and the protective housing respectively, so that sound transmission performance can be ensured; air transmission holes are formed in the outer optical fiber ring supporting thin-walled cylinder, so that an air cavity can be formed between an inner optical fiber ring and an outer optical fiber ring; a hydrostatic pressure self-balancing system is designed based on the air cavity; the inner optical fiber ring and the outer optical fiber ring sense water sound, so as to deform along opposite directions; and the inner optical fiber ring and the outer optical fiber ring are located at different arms of a hydrophone so as to form a push-pull differential structure. The differential structure-based interferometricoptical fiber hydrophone probe of the invention has high sound pressure phase sensitivity; and the sensitivity of the differential structure-based interferometric optical fiber hydrophone probe does not change with water sound.