A digital library is a digital information resource system supported by modern high technology, a next-generation information resource management model on the Internet, and the result of the digitization of library collections, and with the development of society and the accelerated pace of people’s lives, people cannot spend too much time classifying and finding books, so the study of book classification and quick finding in university libraries is very important. This paper mainly researches and analyzes the classification and quick search of books in the university library through the algorithms and methods of digital information technology and finds a better algorithm. This paper mainly conducts experiments on automatic text and support vector machine (one-to-many and global optimization) methods and compares the obtained experimental data, such as classification accuracy, classification time, search time, and other data. The experimental results show that the classification accuracy of these three classification methods is in the range of 86%–94%. However, compared with the two methods of automatic text classification and one-to-many classification, the global optimization classification has the highest accuracy in the sample size of each interval. Among them, the classification time is the lowest for automatic text classification, which is less than 30s, and the one-to-many classification sample takes the most time, and their average fitness is in the range of 24%–27%.