Against the backdrop of modernization in social governance and the reform of juvenile justice, the traditional model of guardianship and rehabilitation for minors involved in criminal activities is confronted with the challenge of poor practical effectiveness. Using the temporal and spatial dimensions of guardianship and rehabilitation practice as its entry point, this study draws on the perspective of time-space sociology and Giddens’ structuration theory. By integrating judicial social work theory with empirical cases analysis, it explores the predicaments caused by a lack of temporal continuity and spatial coordination in the current system, ultimately demonstrating the significant roles of time and space in the rehabilitation process. The research finds that the current rehabilitation system shows a misalignment between “institutional time” and “life time” in terms of time, and a disconnection between “system integration” and “social integration” in terms of space. This disorder in the temporal and spatial structure leads to the “fragmentation” and “suspension” of the rehabilitation practice. To optimize the rehabilitation strategies, this study proposes the construction of a “full-cycle time chain” and a “multi-field spatial network,” integrating the “early warning–mid-term rehabilitation–late-term reintegration” guardianship and rehabilitation timeline with the “family–school–society” guardianship and rehabilitation spatial units through temporal and spatial interaction, thereby promoting the effective allocation of rules and resources in time and space, achieving a positive interaction between institutional structure and daily practice, and providing theoretical inspiration and practical solutions for advancing China’s juvenile justice protection and social governance with Chinese characteristics.