COVID-19 belongs to the category of damp pestilence in Chinese medicine. The key pathogenesis is plague poison blocking the lung caused by exogenous turbid dampness and plague poison lurking the pathogenhidde, motivating shaoyang fire, wood-fire impairing the metal and dampness poison fire uprush. In treatment of COVID-19, we use harmonic method throughout the whole process, strengthening and consolidating basis by protecting middle qi, pectoral qi, and yin fluid. The basic therapeutic principle are dredging qi activity and clearing heat, with combination of frigotherapy and pyretotherapy. Multiple methods are mixed by freeing lung, clearing heat and detoxifying, boosting qi and nourishing yin, activating blood and dissolving stasis, resolving dampness and dredging collaterals, aiming at cutting off the progress of the disease and saving lives.