In order to solve the problems of traditional seismographs' weak anti-electromagnetic interference ability, narrow frequency response range, large volume and high cost of electromechanical feedback structure, a double-ended Mach-Zehnder (MZ) structure interferometric optical fiber geophone is designed. Use liquid silicone to combine the brass mass with the silicone elastomer to form a one-piece push pull structure, adopt ANSYS software to carry out parametric modeling and lumped parameter finite element analysis of the structure, so as to determine the natural frequency of the structure and when resonance occurs maximum composite amplitude. The signals of different frequency bands are collected by oscilloscope for sensitivity test.The experimental results show that the natural frequency of the geophone when resonance occurs is 106.77 Hz, and the relative error with the experimental value is 1.65%, which verifies the superior potential of the interferometric optical fiber geophone.