Under the dual pressures of global urbanization and cultural heritage conservation, historic urban quarters face challenges such as spatial fragmentation, weakened cultural identity, and rigid governance mechanisms. This study aims to examine the urban renewal and conservation models of historic urban quarters in China and South Korea, selecting Shudian Street in Kaifeng, China, and Insadong in Seoul, South Korea, as representative cases. Accordingly, a multidimensional analytical framework is constructed based on urban renewal theory, and the research is conducted using a combination of literature review, policy analysis, and field investigation. The findings are as follows. First, based on dominant actors, the study classifies urban renewal models into four types: government-led, market-led, hybrid-led, and resident-led. A comparative analysis is conducted regarding spatial restructuring, functional layout, cultural inheritance, and governance models. Second, the study finds that Shudian Street emphasizes image reconstruction and administrative efficiency, while Insadong highlights authenticity conservation and a pluralistic co-governance mechanism through the institutional framework of “cultural district.” However, both cases face a common challenge in balancing cultural conservation and commercial transformation, as well as institutional stability and flexible governance. Based on the above findings, this study proposes a comprehensive strategic system that positions the restoration of cultural functions as the core goal, collaborative governance as the implementation basis, incremental spatial optimization as the urban renewal path, and digital governance as the technical support. This strategy not only responds to the current issues of cultural weakening and fragmented governance in Shudian Street but also provides a reference for the systematic urban renewal and practical operation of small and medium-sized historic urban quarters in China.