The invention discloses a remote external modulation optical fiber interference vibration measuring device. The device comprises a laser emitting device, an optical fiber coupler, an optical fiber interferometer main body structure and a processing device; the laser emitting device and the optical fiber coupler, the optical fiber interferometer main body structure and the optical fiber coupler, and the optical fiber coupler and the processing device are connected through optical fibers, wherein the optical fiber interferometer main body structure comprises a shell and a piezoelectric elastic sheet, one end of the piezoelectric elastic sheet is fixed on the shell, the other end of the piezoelectric elastic sheet is suspended, the shell is fixed on bed rock, and an optical fiber between theoptical fiber interferometer main body structure and the optical fiber coupler is fixed on the piezoelectric elastic sheet; when environmental vibration occurs, the shell drives the piezoelectric elastic sheet to vibrate, and a modulation signal is generated. A passive external modulation mode is used, phase modulation of the optical fiber interferometer body structure is achieved, and associatedamplitude modulation can be avoided.