Abstract: Public space is a very important production and living space in ethnic areas. After the development of tourism, the traditional ethnic villages transformed from ‘simple residential’ community to ‘tourist residential’ complex functional community, and the spatial nature and spatial pattern of settlements changed greatly. The traditional public space and new public space need to solve the problems of space identification, path selection, streamline arrangement and reasonable installation of facilities and so on. Based on the example of Tanganzhai, a village of Dong nationality in Guizhou Province, this paper analyzes the accessibility indices, straightness, redundancy path, betweenness, patronage, close facility and clusters of the new and old public space system in mountain settlement walking system by using the urban network analysis (UNA) method to summarizes the relationship of site selection and mountain terrain, village pattern, street system and small space environment, and discusses the path of adaptive development of public space.