<p>Under the influence of rapidly changing traffic conditions, the spatial structure of mountainous county settlements is often difficult to adapt to the evolution of social relations, which leads to issues such as disorganized spatial organization, imbalanced resource allocation, and mismatches between public service supply and demand. To this end, it is urgent to develop a resilient development model through the coordinated regulation of society–space systems. This study takes Lueyang County in the Qinba Mountain area as a case study, analyzes the county settlement system based on the society-space network theory, and establishes a three-dimensional research framework of “space simulation-resilience assessment-spatial optimization”. The study finds that the transportation network in the peripheral areas of Lueyang County has significantly improved over the past decade. The total social demand has increased by 44.32%, and a larger-scale industrial development belt was formed along National Highway G345. The rapid evolution of the transportation network has enhanced the collaboration, stability, and restorability of county settlements by 15.8%, 42.4%, and 22.2%, respectively. Additionally, this evolution has led to the emergence of 2 agglomeration development zones and 3 settlement clusters with strong buffering capabilities. Based on these findings, it is recommended to plan 8 coordinated development zones within the county, establish 19 passenger hubs, focus on developing 28 core communities, and outline 6 types of rural development models with corresponding planning guidelines. This study can provide theoretical support for the coordinated spatial development planning of mountain settlements as well as practical guidance for promoting urban-rural integration, village system optimization, resources allocation, and construction standards in the county.</p>