To provide an optical fiber sensor system capable of removing intensity noise and processing wavelength information from a plurality of fiber gratings at a high speed.

Through a synchronized-sweep wavelength-variable stabilizing light source (a white light source 1, a synchronized-sweep dielectric multilayer film optical filter 9, and a photon number squeezer 12) to sweep wavelengths in synchronization with a clock 8 as maintaining optical output as a light source for an optical fiber sensor system, light of which flow of photons is constant and of which wavelength is swept is made incident onto one end of a fiber grating column connecting body 2, and the spectrum of reflected light is related to a wavelength for every wavelength frame in synchronization with the clock 8 and stored in frame memory 14. The data in the frame memory 14 is transferred according to the clock 8 and subjected to arithmetic processing in a data analyzing device 15 to obtain sensor information such as displacements in wavelength, etc.