This study focuses on the proactive health needs of community residents against the backdrop of aging, taking the prevention and treatment of Alzheimer’s disease in young-old adults as the entry point. It integrates the Fogg Behavior Model (FBM) and experience design theory to explore the proactive health service framework and human-computer interaction design strategies. Addressing issues such as the lag in traditional passive medical systems and the insufficient proactive health design of cognitive impairment prevention products, quantitative questionnaires and qualitative interviews reveal that the core barriers to proactive health include the lack of cognitive training feedback, intergenerational social support, and aging-friendly multimodal interaction. Based on the FBM, strategies are proposed from three aspects: motivation enhancement, capability improvement, and trigger mechanism optimization. Combined with the needs of Alzheimer’s disease prevention and treatment and digital intelligence technologies such as AI large models, a “family-individual-community” three-terminal collaborative interactive service system is constructed. The design practice of the “Brain Health Guardian” platform verifies the effectiveness of the framework in improving the sustainability of cognitive training and family participation, providing an interdisciplinary solution for proactive health management in community settings.