Nuclear power surge pipe temperature monitoring optical fiber sensing system and monitoring method thereof

The invention discloses a temperature monitoring optical fiber sensing system for a nuclear power surge pipe. The temperature monitoring optical fiber sensing system comprises a temperature measuring optical fiber, a demodulator and a computer which are connected in sequence, the temperature measuring optical fiber is arranged in a loop mode along the surface of the surge pipe, the two ends of the temperature measuring optical fiber are connected with the two ends of an optical switch in the demodulator respectively, and the optical switch enables light to enter the temperature measuring optical fiber from the clockwise direction and the anticlockwise direction respectively through switching. And the computer carries out geometric mean value calculation on the ratio of the backward Raman scattering light intensity in the clockwise direction and the anticlockwise direction so as to obtain the real-time temperature of the surface of the surge pipe. Real-time continuous measurement of the pipeline temperature of