Stomach Qi is the focus of diagnosis and treatment in traditional Chinese medicine. The philosophy of "serious disease depends on stomach" is an important principle for treatment of severe and difficult diseases by Men‘s miscellaneous disease academic thoughts in shanxi. Serious disease refers to the course of disease, symptom, state, prognosis and so on. The diagnosis and treatment of corona virus disease 2019 (COVID-19) is not just on lung, but also on spleen and pectoral Qi. The whole body function should be considered first, then adjust lung and spleen, support stomach Qi, adjust body function, and increase pectoral Qi. At last, the patients recover the normal state and cure the disease. As a classical theory, the philosophy of "serious disease depends on stomach" is the clinical practice essence and the best expression of traditional Chinese medicine, which can provide new idea on diagnosis and treatment of COVID-19.