Distributed optical fiber Raman sensing system and method for gas pipe network leakage

The invention belongs to the technical field of distributed Raman optical fiber sensing, and discloses a distributed optical fiber Raman sensing system and method for gas pipe network leakage. The device comprises a pulse laser, a wavelength division multiplexer, a sensing optical fiber, a photoelectric detector, and a data collection system. Pulse laser output by the pulse laser passes through the wavelength division multiplexer and then enters the sensing optical fiber, anti-Stokes light reflected by a sensor passes through the wavelength division multiplexer and then is detected by the photoelectric detector, one part of the sensing optical fiber is arranged in a thermostatic bath, and the thermostatic bath is used for carrying out thermostatic control on the sensing optical fiber located in the thermostatic bath; signals detected by the photoelectric detector are collected and demodulated through the data collection system, and distributed temperature field information along the sensing optical fiber is o