data-language="eng" data-ev-field="abstract">The An-Shi Rebellion is an important stage in both history and literature. Though the study of its impact on Du Fu's works has reached a consensus, there is little study on its impact on his psychology, let alone in-depth and comprehensive results. In this paper, we make a systematic and in-depth exploration of the changes of Du Fu's psychological characteristics before and after the An-Shi Rebellion by analyzing his prose with the big data approaches. The results show that Du Fu's psychology changed significantly before and after the An-Shi Rebellion. He became disappointed with society, devoted more of his affection to the people, and strengthened his desire to save the country and the people. Moreover, the change did not happen overnight, but over a long time period. This work provides a new case for the application of big data technology in psychology research. The findings could help people to understand Du Fu more scientifically and deeply, and to better promote cultural heritage.