According to the academic hall, the source of the thesis topic is nothing more than whether the professor recommended it or chose it himself (according to his own interests, professional expertise, etc.). The self-designed topic of the thesis comes from the accumulation of students' professional courses, which is easier for students with solid theoretical knowledge to get started; It can also come from my observation and thinking in my daily study and life. I am interested in this kind of topic and have my own unique opinions. This kind of paper is easy to come up with new ideas, and students can write with ease. Of course, the above methods are not applicable to students who have a weak foundation and think about problems at ordinary times. They need to choose a theme direction, then read the research literature on this topic in the past five years, find out the shortcomings of previous literature research through a lot of reading, and formulate a topic in combination with current new research methods and technologies.