A new safety system of optical fiber sensors for methane measurement is described based on the near-infrared region absorption mechanism. High detection sensitivity of 120 ppm can be achieved by using wave division mutiplexing(WDM) technique, gas absorption cell with rectangular prism and digital match filter(DMF) for the processing of weak signals which measurement accuracy of wavelength can be highly enhanced. Experiments are carried out by using FLED as broadband light source due to the absorption lines of methane within the low loss window of silica fiber. Results show that the stability and accuracy of this system still need to be improved.