Zhenbao Town，as the "inner" Great Wall，relying on the natural topography of Taihang Mountain，extended from north to the southern part of Hebei，forms an important defense line in the western part of Hebei to protect Beijing from the attack from Shanxi. This paper takes the Ming Zhenbao Town military defense system as the research object, by combing relevant historical materials and using ArcGIS geographic information platform，illustrating the military defense system composition，defense level，military terrain classification and level etc. for qualitative and quantitative analysis，to restore the network defense system formed by interaction between each subsystem for joint defense，summarize the spatial distribution characteristics of military defense systems of Zhenbao Town.