Abstract:A surface temperature measurement method based on FBG-FP sensor is proposed to meet the demand of structural surface temperature measurement. This method can compensate the cross-sensitivity of strain to temperature by acquiring the temperature and strain information of the measured structure through FBG and FP sensing simultaneously. This article analyzes the surface temperature measurement principle of FBG-FP and designs the main parameters of the sensor through simulation. The two-parameter minimum mean square estimation algorithm for signal demodulation of FBG-FP sensor is proposed. Then, a comparison experiment between FBG sensor and FBG-FP sensor is conducted. Experimental results show that the linear fitting correlation coefficient of temperature measurement of FBG-FP temperature sensor is 0. 998 4, and the maximum error percentage is 1. 46% in the range of room temperature to 400℃ , both of which are better than the single fiber grating temperature sensor.