Abstract: Tunable diode laser absorption spectroscopy (TDLAS) is a kind of non-intrusive spectroscopy-based diagnostics, which has been widely used in high temperature gas dynamics research for ground test facilities. The state of the art of TDL-based sensors and their applications for measurements of temperature were reviewed, and species concentrations of gas components in high temperature reactive environments were given in this paper. Particularly, various schemes of absorption detection strategy (direct absorption measurements, wavelength modulation) and related systems were discussed in detail. The recent applications of TDL-based sensors in supersonic combustion, Mars reentry condition and space propulsion research were demonstrated in the final part of the paper.