Abstract:Based on historical documents and fieldwork, this paper restores the defense system of civilian fort-type settlements and finds that there is a tight social organization system within them, and points out that the defense system can be divided into three levels: the outer layer - the joint defense system among settlements, the middle layer - the outer defense system of fort-type settlements, and the inner layer - the internal defense system of forttype settlements. Finally, it is concluded that there are three characteristics of the defense of civilian fort-type settlements: the method of civilian defense is universal, defense is the main focus of attack, and the system is complex with a low victory rate.