Abstract: Based on the method of literature review, the study analyzed the system of Inner Canon of Huangdi and the mechanism of both the diseased and undiseased, and explored the ideological history of the preventive treatment of disease.The result shows that "Sage treating the undiseased" is the spiritual value direction, opening a new thought of "Tao treatment", "inner treatment", and health maintenance, which believes that the inner cultivation outstrips the outer one.The wisdom of preventive treatment in Inner Canon of Huangdi lies in its medical philosophy, which consists of health maintenance, medicine, and Taoism.Preventive treatment is a unification of "Tao" and "art", as well as a combination of cultivation and medicine."Tao", as the fundamental, including the inner care of Qi as well as the cultivation of morality and virtue, is an appreciation of the nature of life and a refinement of the medicine philosophy. Longevity and health can only be obtained by the inner cultivation of morality and virtue which fosters Qi and then the essence of life.