The main purpose of writing graduation thesis is to cultivate students' ability to comprehensively apply the knowledge and skills they have learned, integrate theory with practice, and independently analyze and solve practical problems, so that students can engage in their professional work and carry out relevant basic training. The graduation thesis should show that the author can accurately grasp the basic professional knowledge he has learned, learn how to comprehensively use the knowledge he has learned for scientific research, and have a certain understanding of the research topic. The scope of the thesis topic should not be too broad, and generally choose one side of an important issue in this discipline.