Professional historians usually study and textual research on history from relatively small, specific and detailed points, while civil subjects like to study some big and unreasonable problems from a macro perspective. For example, some people will study the military strength, foreign trade policy, ethnic exchanges, specific prices, etc. of the Northern Song Dynasty from the horse trade in a certain year, but the topic of folk themes is often "Why did the Northern Song Dynasty suffer repeated wars and defeats?" Of course, there are also people like Huang Renyu who can write both the micro-history of water transportation in Ming Dynasty and the macro-history of fifteen years in Wanli. Only by doing a good job in micro-history can we write a convincing macro-history.