Addressing the research gaps, including incomplete analysis of influencing factors, limited scope of study populations, and insufficiently operational support systems, this study aims to extensively analyze the barriers and facilitators to service utilization among both service-engaged and non-engaged families of autistic children by adopting the Consolidated Framework for Implementation Research (CFIR). Additionally, it intends to construct multi-stakeholder action pathways and networks in combination with the Theory of Change, thereby forming an operational rehabilitation support system. The ultimate goal is to enhance the health equity and overall health status of autistic children and their families. A two-phase mixed approach was used: (1) CFIR-based semi-structured interviews and qualitative analysis with structured coding (alphabets for facilitators, numerals for barriers), following COREQ guidelines; (2) ToC-guided translation of CFIR-identified facilitators into stakeholder responsibilities (matched with barriers) to construct a support system with multi-stakeholder pathways/networks. 37 caregivers (30 service-engaged, 7 non-engaged) were interviewed, revealing 9/15 facilitators/barriers for engaged families and 2/9 for non-engaged ones. Universal barriers include high costs, geographical resource gaps, and insufficient caregiver skills. An evidence-based pathway clarifies stakeholder responsibilities to target barriers; a multi-level network defines collaboration among Core, Intermediate, and Collaborative tiers. This study extensively analyzed the barriers and facilitators to rehabilitation service utilization among both service-engaged and non-engaged families of autistic children, addressing the research gaps of incomplete identification of influencing factors and limited representativeness of study populations. It constructed an evidence-based, multi-component action pathway involving multiple stakeholders and a multi-level, multi-stakeholders collaborative network, thereby forming an operational rehabilitation support system. This system provides a reference for global efforts to improve the accessibility, acceptability, geographic accessibility, and affordability of autism services, contributing to enhanced family well-being, improved social adaptability, and better health outcomes. Such a full-chain evidence-based pathway, spanning from problem analysis to solution formulation, offers an analytical framework for advancing health equity and overall health status among vulnerable populations.