Abstract
To address psychological health service gaps among rural left-behind children, this study examines how a socio-technical hybrid intervention model restructures the child protection ecosystem. Drawing on 45 stakeholder interviews from China’s “L Letter-Accompaniment Project,” we analyzed the data through Bronfenbrenner’s bioecological model, social capital theory, and a network-weaving perspective. The findings reveal a “backend-digital, frontend-human” paradigm. At the micro-level, handwritten letters foster compensatory proximal processes by providing low-stakes opportunities for self-disclosure via “weak ties.” At the meso-level, an AI-driven digital platform functions invisibly as a “network weaver,” identifying risks and coordinating school-based interventions without intruding on the children’s analog safe space. At the exosystem level, the program secures continuity through institutional embedding. The study offers a theoretically informed and contextually grounded interpretation of how hybrid intervention can strengthen child protection ecosystems in rural China, with implications for policy and ethical governance in digital social welfare.