Abstract: Radiation-induced skin injury is a common complication in tumor radiotherapy, which seriously affects patients' quality of life and treatment continuity. Based on the theory of "fire-toxin pathogenesis", Professor Wu Mianhua, a renowned national traditional Chinese medicine (TCM) practitioner, holds that its core pathogenesis is "external attack by fire-toxin, damage to yin and consumption qi, and blood stasis obstructing the skin and muscles". The course of the disease presents a dynamic evolution of acute stage (blazing heat-toxin), subacute stage (yin deficiency and blood stasis), and chronic stage (deficiency of both qi and yin). In terms of treatment, the principles of "syndrome differentiation by stages and simultaneous treatment of root cause and symptoms" are adopted: clearing heat and resolving toxin, cooling blood and reducing swelling in the acute stage; nourishing yin and moistening dryness, clearing heat and dissolving stasis in the subacute stage; and benefiting qi and nourishing yin, dissipating stasis and unblocking collaterals in the chronic stage. Emphasis is laid on the combination of internal and external treatment as well as the integration of prevention and treatment. This paper systematically sorts out Professor Wu Mianhua's academic thoughts on exploring the pathogenesis and syndrome treatment of radiation-induced skin injury using the "fire-toxin pathogenesis" theory, and attaches analysis of proven cases, so as to provide theoretical and practical references for clinical practice.