The structural allocation of the leading power is the core issue in the essential medicines selection procedure. Although the Measures for the Administration of the National Essential Medicines List, revised in 2026, has strengthened inter-agency coordination in the selection process, it perpetuates a traditional structure of unitary dominance, rendering public participation a mere formality. The traditional unitary dominance model is mired in the dilemmas of "administrative monopoly" and "technical arbitrariness," urgently requiring the introduction of polycentric governance theory. A pluralistic co-governance paradigm characterized by the sharing of the leading power can effectively delineate the boundaries among public demands, technical rationality, and administrative power. Under this paradigm, a composite selection procedure integrating vertical sequential flow with horizontal multi-party deliberation should be constructed, thereby promoting the substantiation of public participation, the scientific rigor of expert review, and the restriction of government decision-making to formal review, which will lay a solid rule-of-law foundation for effectively guaranteeing the accessibility and affordability of essential medicines.