A high-sensitivity distribution type hydrostatic pressure sensor and a method of measuring fluid environment pressure by using the high-sensitivity distribution type hydrostatic pressure sensor belong to the optical field. The problem of low precision of a conventional hydrostatic pressure sensor is solved. V0 laser and V1 laser, with one fiber Brillouin frequency shift difference, relatively enter into x-axis of sensing fiber and conduct Brillouin scattering. The pulsed light of V2, with one fiber birefringence frequency shift with the V0 laser or the V1 laser is injected into the y-axis of the sensing fiber, and is output after being reflected by a Brillouin dynamic raster. The fiber birefringence change is obtained by measuring the change of fiber birefringence frequency shift when the Brillouin dynamic raster is excited and detected in the sensing fiber, so that the position and magnitude of extraneous fluid environment static pressure applied on fiber are demodulated. The extraneous fluid environment static pressure change information of sensing fiber is obtained by measuring the birefringence frequency shift change of the sensing fiber.