The theory of “turbid evils invading the clear orifice” is a theoretical thought about damp-heat syndrome of upper jiao put forward by Ye Tianshi, a physician in Qing Dynasty, in Wenre lun, which has important guiding significance for explaining the occurrence, development, prognosis and treatment of nasopharyngeal carcinoma. “Turbid evils” covers pathological factors such as damp-heat turbid evils and static blood toxin. “Clear orifice” includes the nose and pharynx and other head-face orifices that connect with the outside world, and the heart that governs the bright spirit. Based on the theory of “turbid evils invading the clear orifice” and the research of western medicine, this paper summarizes that damp-heat turbid evils such as EB virus, alcoholic drink and preserved food are the causative factors of nasopharyngeal carcinoma. The pathogenesis of nasopharyngeal carcinoma is that damp-heat turbid evils invade the body, flow into blood vessels, and form static blood toxin for a long time, which blocks the nasal orifice outward and the heart inward and flows all over the body. At the same time, this paper discusses the microscopic of “ turbid evils invading the clear orifice” in nasopharyngeal carcinoma from the perspective of microenvironment, and based on the theory of “turbid evils invading the clear orifice” and our team’s clinical practice, formulates the differential treatment scheme for nasopharyngeal carcinoma in different stages, in order to provide reference for the clinical application of traditional Chinese medicine in nasopharyngeal carcinoma. [ABSTRACT FROM AUTHOR]