Abstract: The deficiency and sufficiency of the spleen is a significant factor in preventing and treating pestilences. This paper summarized the experiences of preventing and treating pestilences and held that the experience of traditional Chinese medicine (TCM) preventing the pestilences has undergone a process from the theory of cold damage disease to warm disease. As for the therapeutic method of rectifying spleen to treat the pestilences， it was warming spleen and supplementing qi in Qin and Han dynasty， drying dampness and fortifying the spleen in Jin and Tang dynasty， draining heat with cold-cool medicine and boosting spleen yin and attacking pathogen and clearing spleen in Song， Jin， and Yuan dynasty， along with diffusing， venting and removing pathogen with aromatic medicine， clearing up turbidity and awakening the spleen， and restoring qi movement in Ming and Qing dynasty. Based on the incidence， therapeutic method， and prescription of the pestilence， this paper has concluded with the therapeutic thought of rectifying spleen throughout， that is， tonifying spleen and strengthening defensive qi in the prevention stage， activating spleen and dispelling pathogen in the treatment stage， nourishing spleen and reinforcing healthy qi.