In this study, we determine the relationship between the broadband absorption spectroscopy and temperature using Doppler broadening combined with a multilinear shape superposition. First, a method for temperature effects on broadband absorption spectroscopy is proposed, utilizing the principle of a multiple Gaussian line shape superposition. A theoretical expression of the temperature effect on broadband spectroscopy is then presented for the first time to the best of our knowledge, and the variation law of broadband absorption spectroscopy with temperature is explained. Furthermore, the effectiveness of the expression is demonstrated by comparing experimental and theoretical data of the SO2 broadband absorption spectroscopy. The results demonstrate that the correlation coefficient (r) between the experimental and theoretical spectra of SO2 within the temperature range of 298.15-923.15 K is greater than 0.93. The method and expression presented in this Letter can effectively explain the data of previous research.