Fiber bragg grating monitoring device and monitoring method for differential settlement of road subgrade

The invention discloses a fiber bragg grating monitoring device and method for differential settlement of a road subgrade, and the method comprises the steps: drilling a key part of the subgrade in the construction or maintenance process of the subgrade, and assembling a pre-buried protective housing, a plurality of fiber bragg grating strain sensors, a strain mounting assembly, a fiber bragg grating temperature sensor, a plurality of fiber bragg grating tilt angle sensors, a tilt angle mounting assembly and a series circuit are mounted in a pre-embedded protective shell, the assembled functional accessories are inserted into drilled holes, and then grouting treatment is performed; the fiber bragg grating strain sensor can sense roadbed settlement change in real time; the fiber grating temperature sensors connected in series are used for temperature compensation and can monitor the temperature change at the pre-buried part; the fiber bragg grating tilt angle sensor monitors the change of the tilt angle of the