In interferometric fiber sensors,there are the problems that the dependence between the modulation depth of laser frequency modulation and the optical path difference,and the high frequency restriction and nonlinear effect of PZT modulation. In order to resolve the restriction and ensure the fidelity-pickup of micro-vibration signal,a vibration sensor based on all polarization-maintained fiber Mach-Zednder interferometer is presented,in which a fiber waveguide modulator is set and the single-frequency polarization-maintaining optical fiber laser and the phase generated carrier homodyne demodulation scheme are employed. The use of waveguide modulator increases the flexibility and the frequency response range of the sensor and the sensitivity reaches to 10^－5rad/Hz^1/2.