Combined with 4 cases, the pathogenesis, pattern identification and treatment characteristics of COVID-19 in Gansu region were analyzed. Based on the analysis, it is believed that COVID-19 is caused by the invasion of damp-heat toxic pathogens. The disease is located in the lungs, affecting triple energizers. It is easy to spread and change, and the pathological changes are in line with the changes of climatic and regional conditions. At the early stage, pathogenic factors are in the phase of defense-qi, which should be dispersed, expelled, cleared and resolved. If the onset of the disease is on the menstrual period, it is essential to resolve dampness, expel pathogenic factors and relieve the exterior first, and harmonize Shaoyang to prevent heat from entering the blood chamber influencing both the defense phase and qi phase. If dampness stagnates in the lung and the defense phase, it is appropriate to dissipate cold and disperse dampness, clear heat and relieve sore throat. Jianpi Huashi Qingre decoction should be taken after initial recovery until residual pathogens are eliminated completely.