Abstract: Transarterial embolization and infusion therapy are foundational interventions for conditions including hemorrhage, vascular malformations, and benign/malignant tumors. However, the prevailing nomenclature for these procedures (e.g., “hepatic arterial infusion chemotherapy”, “bronchial artery embolization, BAE”) suffers from a fundamental limitation: naming conventions based on a single target artery conceptually constrain the therapeutic objective, overlooking the pathological reality that lesion perfusion is sustained by a dynamic, three-dimensional network of multiple arterial sources and collateral channels. This cognitive bias is a common underlying cause of high postoperative recurrence rates, suboptimal efficacy, and complications such as non-target embolization. To address this systemic issue, this paper introduces a universal new theory—“watershed vascular embolization”—based on vascular anatomy, hemodynamic principles, and clinical practice. This theory defines the complete functional blood supply unit of a lesion as a “watershed vascular”, advocating for a shift in therapeutic focus from occluding individual vessels to managing the entire dynamic perfusion network. Using conventional BAE as a paradigm, this article elaborates the conceptual framework and clinical significance of watershed vascular embolization, aiming to reshape interventional thinking and provide a novel theoretical paradigm and practical guidance for enhancing the thoroughness, safety, and long-term outcomes of vascular intervention.