In this paper, a novel one-degree-of-freedom micro-seismic sensor based on Fiber vibrating wire is put forward. The oscillator is penetrated by the optical fiber and mounted near the grating to make a micro-seismic detecting structure. This design contributes to fiber Bragg grating’s response to tiny vibration directly. Some advantages such as small volume, high sensitive, easy for multiplexing, immunity of electromagnetic interference, low cost will be obtained. The new sensor with convenient zero adjust structure is fabricated as well. An experimental system based on high speed FBG interrogation analyzer is set up to demodulate vibration signal and analyze testing data. The micro-seismic simulation experimental results indicate that the sensor owns good performance with low frequency and high sensitivity. This study will be meaningful and helpful in Engineering seismic detection and Earthquake prediction application.