The invention discloses a reflection point array fiber phase-sensitive OTDR sensing system and method. The system comprises an optical pulse generator, a circulator, an optical fiber coupler and a reflection point array. A first port of the circulator is connected with the output end of the optical pulse generator; a second port of the circulator is connected with the reflection point array; and a third port of the circulator is connected with one port of the optical fiber coupler. The sensing system also comprises a first Faraday rotation mirror and a second Faraday rotation mirror, which are connected with the optical fiber coupler; a time delayer is arranged between the second Faraday rotation mirror and the optical fiber coupler; light signals reflected by the two Faraday rotation mirrors are subjected to interference at the optical fiber coupler. The sensing system also comprises a data acquisition and control card, a radio frequency signal source, a first photoelectric detector and a second photoelectric detector. The requirement of the system for a light source is reduced; and the signal-to-noise ratio and sensitivity of the system are improved.