Abstract: The characteristics of tunable diode laser absorption spectroscopy (TDLAS) gas detection technology are high resolution, low detection limit and fast response speed, it has been widely used in on-line monitoring of ambient gases. The gas composition is complex in coal mines. Traditional gas sensors, chromatographic analysis and spectroscopic analysis techniques are limited by the method itself or the environmental conditions on site, and there are different degrees of limitations. Firstly, we introduced the working principles and characters of TDLAS gas detection technology. Secondly, the development process and research status of TDLAS technology in the fields of fire protection, petrochemical, environmental protection and coal mine gas detection are focused on analyzed. Finally, the application effect of this technology in downhole methane gas detection and online monitoring of multiple mixed gases is analyzed.