The invention discloses a distributed optical fiber vibration sensor. The distributed optical fiber vibration sensor is characterized in that: on the basis of the optimized combination of the interference principles of a Sagnac interferometer and a Mach-Zehnder interferometer, the distributed optical fiber vibration sensor comprises a signal processing device, a first sensing optical fiber, a second sensing optical fiber, a third sensing optical fiber, a wideband light source, a narrowband light source, an optical circulator, a first optical wavelength division multiplexer, a second optical wavelength division multiplexer, a first coupler, a second coupler, a third coupler, a fourth coupler, a Faraday rotating mirror, a first photodetector, a second photodetector, a third photodetector and an optoisolator. The distributed optical fiber vibration sensor has a simple structure and can be used for monitoring outside disturbance and positioning multi-point interferences in real time; the demodulation work is relative simple and polarization maintaining optical fibers can be prevented from being used; and by adopting the Faraday rotating mirror, the phenomenon of polarization state fading due to double refraction can be also compensated.