In order to achive three-dimensional seismic wave, a three component fiber Bragg grating(FBG) geophone is designed, and the natural frequency and sensitivity of the seismometer are theoretically deduced. Matlab software and COMSOL software are used to optimize the structure parameters and analyze the modal of the seismometer. The amplitude-frequency response, transverse anti-interference performance and sensitivity response of the geophone are tested. The experimental results show that the flat region of geophone is 0.6~50 Hz. The natural frequencies of the first, second and third order are 56 Hz, 59 Hz and 63 Hz, and the sensitivities in x, y and z directions are 218.22 pm/g, 284.76 pm/g and 249.67 pm/g, respectively. The transverse anti-interference degree in each direction is less than 5%, and the three component detection of low-frequency signal can be realized.