The role and significance of traditional Chinese medicine(TCM) in preventing and treating coronavirus disease 2019(COVID-19) through regulating human immunity was explained from three aspects:the first is the prevention and treatment methods of strengthening body resistance, eliminating pathogenic factors and harmonizing yin and yang, the second is the guiding principles of identifying etiology based on differentiation of symptoms and signs and treating in accordance with pattern identification, and the third is the core connotation of “preventive treatment of diseases”—preventing diseases before the occurrence and preventing changes of existing diseases. It is believed that TCM can effectively prevent and treat COVID-19 due to its unique theory of “healthy qi”, which shares something in common with the connotation of modern immunology.