Abstract: As a product service scenario empowered by Internet technology for doctor - patient interactions, Internet-based diagnosis and treatment (IBDT) holds significant value in promoting the balanced allocation of high-quality medical resources. However, the IBTD service system has not yet formed a closed loop for sustainable development in China. As people′s health care demands keep increasing, China′s IBDT service system needs to build a deep-rooted health care service chain, transforming from a single passive diagnostic and treatment approach to comprehensive proactive health management. On the basis of literature review and theoretical deduction, this paper finds that the realization of this transformation relies on the joint efforts from the macro policy level, meso functional level, and micro technological level. And the symbiotic evolution of the internal ecosystem and external environment of IBTD is the key to its successful transformation. At the level of internal ecosystem, the synergistic development of multiple service subjects is the core for maintaining the sustainable development of IBTD, in which digital intelligence empowerment is the major path for the digital transformation of IBDT. Specific suggestions include establishing a community-centered digital medical community for core clinical services and remote joint clinics; enriching the service hierarchy and constructing a full-process service chain of proactive health management covering pre-diagnosis, in-diagnosis, and post-diagnosis closed-loop services to provide patients with comprehensive and continuous diagnosis and treatment services; and establishing an appropriate bilateral incentive mechanism to satisfy the interests of multiple subjects and achieve the incentive compatibility between physicians and patients. At the level of external environment, it is necessary to create an IBDT-friendly external environment from the political, economic, social, and technological aspects, thus providing opportunities and external driving forces for the digital and intelligent transformation of IBDT.