A fiber grating temperature monitoring system based on the fiber Bragg grating analyzer (FBGA) demodulation module is constructed, and the temperature monitoring for the external environment is realized. The peak wavelength of the reflected light is obtained through the digital signal processing module in FBGA, and the fitting method is used to obtain the relationship between the peak wavelength and the temperature. LabVIEW is used to write the corresponding upper computer program. The measurement accuracy of the proposed measuring method is high. Compared with the constant temperature experiment, the temperature error of the proposed system is within ±0.5 ℃, the system response time is less than 0.5 s, and the temperature sensitivity of the system is about 0.1 ℃. When the confidence level is 95.40%, the repeatability index is within ±0.0210%.