Abstract: This paper takes the preventive treatment of disease concept in Traditional Chinese Medicine (TCM) as its core theoretical support, deeply analyzes the cognitive logic of TCM regarding the occurrence and development of viral diseases (belonging to the category of exogenous epidemic diseases), and systematically expounds the core connotation and mechanism of action of the environmental regulation-trend-conforming pathogen expulsion strategy. Environmental regulation improves the body’s imbalance of yin and yang, disorder of qi and blood, and other states through syndrome differentiation and treatment, destroying the pathological environment on which viruses depend for survival; trend-conforming pathogen expulsion guides the excretion of pathogenic factors through sweating, vomiting, purging, and other approaches in accordance with the development trend of diseases and the law of the human body’s pathogen excretion. This strategy integrates the three dimensions of preventing disease before its onset, preventing progression of existing disease, and preventing recurrence after recovery throughout the entire cycle of prevention, treatment, and rehabilitation of viral diseases. It not only conforms to the characteristics of TCM’s holistic view and syndrome differentiation and treatment but also provides a new idea for the prevention and control of modern viral diseases that focuses on regulation and guidance, which is of great practical value for improving the prevention and treatment system of viral diseases.