In order to optimize the rapid evaluation method and efficiency of asphalt aging characteristics, the infrared spectral information evaluation method of asphalt with different aging degrees was optimized based on DTW (dynamic time warping) algorithm, and the spectral information similarity SIS(spectral information similarity) evaluation index of aging asphalt is proposed. The results show that the minimum regularized distance based on DTW algorithm can reflect the amount of information about the cumulative changes in the structure of all chemical compositions in aged asphalt, which in turn indicates the degree of thermo-oxidative aging of asphalt. The correlation coefficient between SIS and the main characteristic peaks (sulfinyl and carbonyl) is not less than 0.954 4, which is strongly correlated with the aging degree of asphalt. The dispersion coefficient of the SIS index can be reduced by 92% compared with the single-component characterization index, which significantly reduces the probability of misclassification of the evaluation results of infrared spectral pattern. It shows that by combining with single-component qualitative evaluation, the SIS index can be used as the basis for evaluating the aging degree of asphalt, and the evaluation method can also be used as a reference for spectral information similarity identification and categorization research.