The invention relates to a localization device and a localization method for electrical equipment partial discharge source. The device comprises six cylindrical sound pressure sensing primitives (1). The end part of each cylindrical sound pressure sensing primitive is provided with a fiber small hole (2). The end part of each cylindrical sound pressure sensing primitive is fixed with an elastic membrane (3). The internal of each cylindrical sound pressure sensing primitive is a coaxial hollow circular column, and each cylindrical sound pressure sensing primitive is internally provided with an elastic column (4) fixed on the bottom. Each elastic column is coiled with a fiber. The tail end of the fiber is plated with an aluminium membrane of high reflectivity. A laser emitted by a laser diode is input into an optical coupler via an optical isolator. Reflected interference light enters a photoelectric probe. The device adopts the differential structure, and thus isotropic noise in electrical equipment is offset in principle, thereby improving the signal to noise ratio. The invention adopts a method of locating the partial discharge source with the direction finding line minimum inscribed circle center principle. The invention can respond to supersonic signals of low energy, and has advantages of high sensitivity, large dynamic scope, anti-electromagnetic interference and high reliability.