The massification of socialist core value system is a process of social psychology enhancement, and mass media has a double impact on social psychology. In view of this, this paper explores the influence mechanism of mass media on social psychology in the process of massification of socialist core value system by using text mining method. Taking the relevant news reports of five mainstream media as the research samples, the TF-IDF algorithm, the LDA theme model and the sentiment analysis method are comprehensively applied to classify the reported themes and explore the dynamic evolution of the themes and the public sentiment. The study shows that the mainstream media focuses on the construction of macro-political themes such as the state, law, human rights and so on, while the disclosure of the case and the more caring and proximity of the audience are not as important as the former in the reporting of the incident. And there are obvious differences in the heat and emotional tendency of different themes as well as theme words in time. Therefore, based on the political science perspective, it is proposed to promote the popularization process of the socialist core value system by innovating the missionary path, promoting the universal popularization of the core theory, and emphasizing the participation of multiple subjects.
