Yang Bawei, originally named Yang Yansan, was a famous physician in northern Sichuan during the late Qing Dynasty. This article focuses on the medical theories and cases related to the epidemic caused by Yang Bawei in the handwritten manuscripts of Yang‘s posthumous works, and explores the "epidemic based heat syndrome" ideology of "Yang Bawei". It is reflected in adhering to the principle that those who transmit the "Inner Canon of Huangdi" are all heat syndrome, and cold syndrome is not transmitted; "The Treatise on Cold Damage" is a book for treating fever and also a book for treating epidemics; plague is caused by the venom of the mouth and nose that subdues the membrane; at the beginning of the epidemic, the six meridians were used for differentiation, and over time, the eight principles were used for differentiation; the principle of using drugs for epidemic diseases should be spicy and cool, and caution should be taken against dry heat, bitter cold, and warm tonifying. Due to the author‘s limited knowledge, errors are inevitable. The purpose is nothing more than to arouse the interest of fellow researchers and discussions, and to serve as a guiding stone.