Generation, papers are often used to refer to articles that conduct research in various academic fields and describe academic research results, which are referred to as papers for short. It is not only a means to discuss problems in academic research, but also a tool to describe academic research results in academic exchanges. Including academic papers, graduation papers, dissertations, scientific papers, achievement papers and so on. It is selected from the title, abstract and text of the paper, and it is a vocabulary with substantive significance to express the central content of the paper. Keywords are words used by computer systems to index the content characteristics of papers, which are convenient for information systems to collect and provide readers with retrieval. Generally, 3-8 words are selected as keywords for each paper, and a new line is set at the bottom left of the abstract. Subject words are standard words. When determining the subject words, we should analyze the theme of the paper and convert it into standard words in the thesaurus according to the rules of indexing and collocation.