Objective: The paper analyzes the deep-seated obstacles faced by hierarchical diagnosis and treatment, explores the internal mechanism by which smart healthcare addresses this challenge, and constructs an operable implementation path. Methods: Using Chengdu City as a sample and moving beyond the existing "technology tool theory" perspective, the grounded theory method was applied to conduct in-depth interviews with key managers of primary healthcare institutions to systematically diagnose the deep-seated obstacles in hierarchical diagnosis and treatment, and explore the internal logic through which smart healthcare solves these problems. Results: Hierarchical diagnosis and treatment in Chengdu City faces a systemic dilemma composed of macro-level institutional failure, micro-level motivational distortion, interrupted collaborative processes, and difficulties in technology application; the breakthrough path of smart healthcare lies in following four internal logics: resource integration, collaborative cooperation, risk control, and data empowerment, which correspond respectively to restructuring spatiotemporal efficiency, reshaping incentive trust, clarifying responsibility and traceability, and driving evidence-based decision-making. Conclusion: Considering the current situation in Chengdu City, efforts should be made in four dimensions—top-level design optimization, incentive mechanism reconstruction, collaborative process assurance, and data governance deepening—to construct a new hierarchical diagnosis and treatment ecosystem driven by both technology and institutional mechanisms, providing practical references for the high-quality implementation of hierarchical diagnosis and treatment driven by smart healthcare nationwide.