First of all, we should be familiar with the domestic and foreign literature related to the subject. This sentence is easier said than done. How many documents should I read in my own discipline? The subject is an undergraduate and can't ask for anything. Personally, in my research field, I finished three or four thousand foreign language documents a few years ago. However, I still dare not say that I am familiar with the research status at home and abroad. The research status is dynamic, so we must read the domestic and foreign literature persistently. The next step is to classify the read literature and classify the similar content into one category, which can also be called genre. For each genre, sort out the ins and outs in chronological order. Then compare different schools, analyze their similarities and differences, and analyze the advantages and disadvantages of each school. After doing the above work, it is natural to find out the research status at home and abroad. In fact, literature review is the place that can best reflect a scholar's academic foundation.