Abstract: In recent years, the increasing demand for diverse evidence in medical research and the support of big data and artificial intelligence technologies have pushed real world research into the focus of attention around the world. To fully understand the application of real world research in the medical field and explore the differences and difficulties in methodology, this review has combined the published papers from PubMed and CNKI, and classified them into three categories:clinical problems, drug problems, and traditional Chinese medicine(TCM) problems. In addition, the research design, sample size, statistical analysis and other methods used in the study have been summarized, with problems discussed and solutions provided, so as to make the most of the real world research.