Optical fiber grating strain sensor

The utility model discloses an optical fibre grating strain sensor which comprises a bowstring elastic fold line assembly, optical fibre grating, and an end seat, wherein the bowstring elastic fold line assembly is composed of two bowstring elastic fold line components which are symmetrically arranged up and down, and two ends of the bowstring elastic fold line assembly are respectively fixed on the end seat; the optical fibre grating is positioned between the two bowstring elastic fold line components and is fixed at two ends of the bowstring elastic fold line assembly; and each bowstring elastic fold line component is provided with at least one bending part which is flexed when in the axial stress. The testing range of the optical fibre grating strain sensor can flexibly be adjusted according to the practical situation, thereby multiple application environments can be adapted; the zero wavelength of the optical fibre grating strain sensor can be adjusted after the optical fibre grating strain sensor is installed, so the problem of the zero wavelength shift caused by the installation is avoided.