Abstract: Focusing on the phenomenon of adjacent isolation in urban central districts, this study investigates its formation mechanism and existing issues, and summarizes its characteristics and impacts. Through field research on a typical adjacent isolated residential area in the central district of Nantong City, problems were identified and analyzed using research methods. Finally, the theory of defensible space is introduced to propose feasible strategies for the environmental design of adjacent isolated residential areas in urban central districts from the perspectives of spatial environment, public space, road space, and interpersonal communication, aiming to strengthen resident interaction and promote residential integration.