COVID-19 falls into the scope of pestilence in traditional Chinese medicine.Prof.Wang Qingguo thinks that its core pathogenesis is dampness pathogens and at the disease onset, it can be combined with the cold pathogen, heat pathogen, as well as fluid consumption, and so on.During the treament, its pathogenesis is complex.It may transform into heat, or into dryness, and it may impair yin or stir up blood.Some may recover after pathogens are dispelled from the surface, some may penetrate into the interior due to mistreatment, and some may stay in the position of half exterior and half interior for a prolonged period of time.Among those with transition into the interior, some may affect the lung, some may affect the spleen and stomach, Jueyin pericardium may be affected in some.Internal closure and external detachment are important disease mechanism in the critical stage.Thick and greasy coating on the tongue is the typical tongue image of the disease, therefore, the coating change on the tongue plays an important role in judging the patient’s condition.Early treatment is critical.Ideal curative effects can be obtained by sticking to the principle of eliminating evils and avoiding using the herbs(medicines)that are too cold or too hot in nature.This paper analyzed 4 confirmed or suspected cases of COVID-19 treated by Professor Wang Qingguo in order to provide references for the clinical treatment of the disease in traditional Chinese medicine.