Abstract: The analysis instrument is gradually spread in the field of coal mine safety monitoring, which is designed on the principle of tunable diode laser absorption spectrum detection technology (TDLAS). The spectrum analyzer has many advantages, such as high precision, wide measuring range, low measurement error, long calibration cycle, no affect from water vapor, dust and other interference gases, etc. In this paper, the design idea and design scheme is elaborated for the various gas spectrum analyzer by TDLAS technology.