A fiber Bragg grating (FBG) micro-seismic geophone based on a hinge connection structure is proposed in this paper.The sensitivity and resonant frequency are theoretically studied.The effects of the connection position of the optical fiber and the moment of inertia of the mass on sensitivity and resonant frequency are discussed.An optimization method to ac hieve a high sensitivity and high bandwidth is proposed and simulated by using the fin ite element method.The sensor sample was fabricated and tested using a commercial demodulator.A sensitivity above 40pm/g and a resonant frequency of 1kHz are achieved,and the equivalent noise is 0.1mg/Hz.The sensor ca n be better us ed in micro-seismic monitoring for high-frequency weak seismic signal detectio n.