Abstract: Liu Wansu is a representative of the Hejian School, and his academic system is dominated by the theories of “restraining excessiveness to acquire harmony” and “fire-heat theory.” The concept of “restraining excessiveness to acquire harmony” first appeared in Suwen(Plain Questions), and its specific connotation has been continuously expanded by subsequent generations. For example, Liu Wansu used various phenological phenomena in nature as the foundation for further linking the pathophysiological phenomena of the body. At the same time, Liu Wansu highly values his theory of disease caused by fire-heat pathogens. He re-exposed the theory of disease caused by “six Qi” based on “pathogenesis item 19.”He not only greatly expanded the types of fiery diseases, but also creatively proposed the conclusion that “six exogenous pathogenic factors transfer from fire”. Through researching a large amount of data, we believes that the “stagnation syndrome theory” is the internal bridge linking the “restraining excessiveness to acquire harmony” theory and the “fire-heat theory” theory. Based on the idea, subsequent generations of doctors consistently supplement the depression syndrome theory. As a result, the following discussion is based on this, and we believe that combining related theories will be more conducive to Liu Wansu's academic thoughts research, and better apply them to clinical practice.

Key words: restraining excessiveness to acquire harmony, fire-heat theory, depression syndrome, Liu Wansu, the four great masters of the Jin and Yuan dynasties