Books are meaningful for retrieval. By searching a large number of documents, students can taste life in various ways and gain unlimited knowledge and skills in a limited time. Today's successful people are good at collecting, processing, processing and applying knowledge and information. The ability of document retrieval has become one of the important qualities that today's society should have. With this ability, we can say that we have the ability foundation of lifelong learning, which can help people solve all kinds of difficult problems that may be encountered in lifelong learning and work, master the methods of acquiring knowledge, and make themselves more smooth in the process of receiving new education and acquiring new knowledge.