Physiology of traditional Chinese medicine holds that physical phenomena, as an important manifestation of human life activities, are closely related to health and disease. Constitution determines our health status, our susceptibility to certain diseases, and the reaction form, treatment effect and prognosis after illness. Therefore, it is of great significance to apply TCM constitution classification theory, identify constitution types according to the reaction state and characteristics of different constitution types, adopt classified management methods, formulate prevention principles according to individual needs, and choose corresponding prevention, treatment and health care methods for constitution nursing. Constitution identification is based on TCM constitution classification. The classification of TCM constitution is divided into several types according to the different morphological structure, physiological function and psychological state of individuals in the crowd, according to certain standards and using certain methods, after sorting out, analyzing and summarizing. After nearly 30 years of research, according to the morphological structure, physiological function, psychological characteristics and reaction state of human body, TCM constitution can be divided into nine types: peace, qi deficiency, yang deficiency, yin deficiency, phlegm-dampness, damp-heat, blood stasis, qi stagnation and connotation.