"Three Books on Medicine by Zheng Qin'an" is a work handed down from generation to generation by Zheng Qin'an, a famous doctor in the Qing Dynasty. It includes three classics: "The True Biography of Medical Principles", "The Yuantong of Medical Methods" and "The Persistent Treatise on Febrile Diseases". The book deeply explains the theory of yin and yang of traditional Chinese medicine, details the pathogenesis and treatment methods of clinical testimony, and emphasizes the treatment of external injuries and internal injuries, which is unique in its own way. This book has a very high reference value for the clinical practice of traditional Chinese medicine. It is an indispensable and valuable heritage for the field of traditional Chinese medicine and is worthy of in-depth study by medical enthusiasts.