Differential absorption lidar has the characteristics of long detection distance, high sensitivity, and fast response. It can be used for remote sensing of large-scale atmospheric toxic and harmful gases, and has become the focus of the development of atmospheric toxic and harmful gas laser telemetry technology in recent years. Firstly, the basic principle of differential absorption lidar atmospheric telemetry is described. Secondly, the development status of the technology is analyzed from two aspects of laser application and system platform development. Finally, the development direction of wide spectrum, multi-wavelength, new detection system lidar, multi-platform application and composite system will become the future toxic and harmful gas telemetry.