Abstract: In the context of Rural Revitalization, an important issue is how to sustain the historic spatial pattern of defensive traditional villages while meeting contemporary needs for conservation and revitalization. As a key carrier of collective memory, public space in traditional villages serves both practical functions and ritual expression. Taking Huangsiyang Ancient Enclosed Village in Huidong, Guangdong, as a case study, this paper combines historical document review, field investigation, and Space Syntax analysis to examine the identification of its enclosed-walled system, as well as the formation, evolution, and mechanism of its public space. The results show that the public space of Huangsiyang Ancient Enclosed Village gradually evolved through the interaction of traffic axes, defensive boundaries, and social institutions. Pingxi Ancient Road functioned as the main organizing axis, while the enclosed-walled system shaped an inwardly concentrated yet outwardly sparse spatial pattern through boundary control. Ritual and official residential buildings further reinforced the hierarchical order and cultural symbolism of public space. On this basis, the evolution of public space in Huangsiyang Ancient Enclosed Village is summarized as 'axis guidance-boundary constraint-institutional reinforcement', and corresponding conservation strategies are proposed to support the integrated conservation and adaptive renewal of public space in defensive traditional villages.