Abstract: As an interdisciplinary subject, Digital Humanities emphasizes the integration and development of computing technology and humanities. Ancient Chinese classics is an important part of the study of humanities. In this context, we use computer technology to extract keywords from the digitized classics of the Spring and Autumn period, so as to analyze the distribution of keywords in the classics of the Spring and Autumn period. In this paper, three keyword extraction algorithms are used, which are based on unsupervised textrank algorithm, traditional TF-IDF algorithm and LDA topic model algorithm. Based on evaluation method of pooling, it is found that textrank algorithm can extract better keywords with an accuracy of 84%. The accuracy of traditional TF-IDF algorithm and LDA topic model algorithm is 62% and 74% respectively. At the same time, according to the keywords drawn out, we can find that the chronicles of the Spring and Autumn period mainly focus on the interrogation, alliance, expedition, marriage and funeral, usurpation and killing among the vassal states. Keywords Digital Humanities, TextRank,