The research status at home and abroad, that is, literature review, should be based on literature review and related to research issues, but not too limited. If it has nothing to do with the problem, it is infinite; Too limited violates the principle of interdisciplinary and infiltration, which narrows the field of vision and stifles thinking. The so-called "synthesis" of review is synthesis, which synthesizes the research survey of a certain subject field in a certain period; "Narration" is not just narration, but comments and comments, that is, the author must have his own unique views. We should pay attention to analysis and research, be good at finding problems, and highlight the position, advantages and breakthrough points of the subject in current research; It is an obvious mistake to abandon prejudice and not quote opinions contrary to your tutor and yourself. The object of review, besides ideas, can also be materials and methods.