With the rapid development of computer technology and Internet, online query, retrieval and download of professional data has become an important means of scientific and technological information retrieval. For all kinds of full-text databases or abstract databases on the Internet, abstract index is an important tool for readers to retrieve documents, which provides convenience for the construction and maintenance of scientific and technological information literature retrieval databases. It is a comprehensive introduction to the paper, so that people can understand the main contents of the paper. After the paper is published, abstract magazines or various databases can directly use the abstract without modification or slight modification, so that readers can know the main contents of the paper as soon as possible. In order to supplement the deficiency of the title and avoid misunderstandings, deficiencies and even mistakes that may occur when others write the abstract. Therefore, the quality of abstracts directly affects the retrieval rate and citation frequency of papers. Under normal circumstances, online defense should have a stable network environment, and students should be equipped with computers, cameras, microphones and other electronic equipment needed for online defense. Install relevant communication software in the equipment used in advance, and the defense environment requires bright, quiet and undisturbed light. Overcome nervousness, anxiety and uneasiness, and be confident that you can successfully pass the defense. Pay attention to self-cultivation and be polite to guests. Whether listening to the teacher's questions or answering them, you should be polite. Understand the meaning of the question, grasp the main idea of the question, understand the purpose and intention of the defense teacher, fully understand the root of the question, and then answer it to avoid the phenomenon of irrelevant answer.