The invention discloses an optical fiber delay line-based distributed optical fiber vibration sensing system, which comprises a light emitting unit, an optical fiber ring element which is connected with the light emitting unit and a sensing optical fiber, a beam splitter which is connected with the optical fiber ring element and used for splitting a backscattering light beam into a first backscattering light beam and a second backscattering light beam and outputting the backscattering light beams respectively, an optical fiber delay line which is connected with one output end of the beam splitter and used for delaying the second backscattering light beam, a light combiner which is connected with the optical fiber delay line and the other output end of the beam splitter and used for combining the first backscattering light beam and the delayed second backscattering light beam, an APD light receiving module which is connected with the light combiner, an AD collector connected with the light receiving module, and a light analysis and display system which is used for analyzing the electrical signal collected by the AD collector to obtain the vibration position of the sensing optical fiber. The system has the advantages of high positioning precision and high interference measurement technique sensitivity.