A real-time detection system of methane concentration for mine was desiged according to the characteristic absorption spectrum of methane.Based on the analysie of wavelength of the characteristic absorption spectrum of methane,static Fourier transformation interferometer and linear CCD detector were adopted to obtain the spectral information,sequentially,the attenuation decrement of luminous intensity of the spectrum with different wavelengths was calculated.By simulation computation,the functional relations of the intensity of incident light and outgoing light with methane concentration were present out,on these grounds,a laser with power of 10 m W was adopted to the real-time detection system.A expression of methane concentration was given out based on Lambert-Beer theorem and concentration-path length product formula.The least detection concentration of methane for the real-time detection system is 0.02%.The detection system can meet the demand of detecting mine methane with the concentration of 0 to 5% and the detection precision of 0.1%.The experiments proved that using Fourier transformation spectroscopic analysis to solve methane concentration can meet requirement of real-time detection of mine methane.