In the process of applying the tunable diode laser absorption spectroscopy to detect the gas concentration， the selection of the characteristic absorption spectral lines of the gas to be measured affected the system sensitivity and the characteristic absorption spectral lines were affected by the temperature. In this paper， a study was conducted on the selection of the characteristic absorption spectral lines of hydrogen and the temperature-dependent mechanism of the characteristic absorption spectral lines. The results showed that I_pand FWHM of the H₂ absorbance curve decreased with the increase of temperature（200~300 K）. The integrated absorbance decreased significantly under the dual effect of the I_p and FWHM； the Q（T） of H₂ increased linearly with the increase of temperature and rQ had the greatest weight among the factors influencing the intensity of the spectral lines， which finally led to the decrease of intensity with the increase of temperature.This research could provide a theoretical basis for temperature compensation of hydrogen sensors based on tunable diode laser absorption spectroscopy.