Find problems and choose topics from the gap between social needs and existing production technologies and means; (5) The topic selection should start with simplicity and concreteness. Especially for graduate students, when they begin to engage in research and scientific and technological inventions, they should try their best to start from simplicity, and as a subject, they must start from specific and meticulous things, so as to build confidence and do a good job in the subject; (6) The topic selection should be combined with personal professional expertise, interest in learning and the research direction of the tutor. The process of topic selection is generally divided into two steps: one is subject investigation. Mainly through literature retrieval and field research to collect data, and then sort out and analyze the data. The second is to determine the topic. According to the general principles and methods of topic selection, make use of the relevant data of investigation to determine the topic selection and write the opening report. The opening report usually includes: (1) Why you chose this topic; (2) Research status and existing problems at home and abroad; (3) What are the researchers' new viewpoints and ideas on this issue? (4) What aspects should researchers start with and what ideas they have; (5) List references.