Topic modeling is a digital method to discover hidden thematic structure in large collections of unlabeled texts. It is now widely used to analyze massive modern Chinese texts from internet pages, new media and social net, like document classification and clustering, hot event detection and tracking, opinion mining and so on. This paper uses topic modeling in the analysis of the top-three classical works of pre-Qin Confucianism to discuss their ideological inheritance and development. The aim is to cast a new light on "close and direct reading" of classical Chinese texts through "distant and machine reading" and encourage some more creative usage of digital methods in the research of Chinese classical works.