Natural gas pipeline leakage optical fiber monitoring system and method

The invention relates to the technical field of natural gas pipeline leakage monitoring, in particular to a natural gas pipeline leakage optical fiber monitoring system and method. The system comprises host equipment and a monitoring optical cable, and the host equipment comprises a laser, a beam combiner, an optical modulator, a multi-channel optical switch, a wavelength division multiplexer, a photoelectric detector and a master control and signal acquisition processing circuit which are connected in sequence; the monitoring optical cable comprises a transmission optical cable and a sensing module, the transmission optical cable is composed of a multi-core single-mode optical fiber, and the sensing module is composed of an external protective shell, an internal light beam splitting unit and an internal sensing air chamber. According to the invention, the quasi-distributed optical fiber sensing technology and the laser gas detection technology are combined, and the laser gas detection technology is utilized