Aiming at the problem of deficient demodulation precision in fiber Bragg grating ( FBG) demodulation system caused by wavelength drift in a variable temperature environment, a grating method for FBG sensing system based on Fabry-Perot (F-P) standard for nonlinear wavelength drift calibration was proposed. In this paper, the FBG demodulation system based on the F-P standard is established, the wavelength calibration process based on the nonlinear error compensation of the F-P standard is designed, and the simulation experiment system of the FBG demodulation system in the practical application environment of aerospace is built, and the experimental tests are carried out in the constant temperature and variable temperature environment. The experimental results show that the demodulation stability of the sensor system is within ±0. 6 pm and ±1. 1 pm under constant temperature and variable temperature, and the wavelength drift of the sensor system demodulation decreases from 20. 3 pm to 0. 7 pm under variable temperature. The accuracy and stability of the method are verified, which provides a reference for structural health monitoring in aerospace and other fields.