Mental state is an important part of the normal life activities of the human body, and it is also the most external expression and the most easily obtained information of the physical condition. The normal activities of the mind depend on the normal operation of the viscera, qi, and blood, and are a unified whole that prospers together and suffers together. The theory of the five-spirit-viscera in the Yellow Emperor’s Inner Classic revealed that the normal mental activities of the human body were dominated by the five internal organs, that is, the five internal organs were the body and the five spirits were the function. And it highlighted the viewpoint that the five internal organs store the spirits and are actually one. The heart governs the spirit and belongs to the four internal organs. On this basis, Synopsis of Golden Chamber used the internal organs to diagnose and treat mental diseases, integrating the theory of the five spirits into it, forming a unique method of diagnosis and treatment with the heart as the leading factor and regulating the qi and blood of the four internal organs. It identified the pathogenesis of diseases such as pathogenic crying, lily disease, and hysteria from five levels: heart deficiency and weak qi, heart-lung disharmony, heart-liver disharmony, the heart of the loss of the spleen nourishment, and disharmony between heart and kidney. The treatment was mainly to replenish the deficiency of the viscera and eliminate the pathogens, reflecting the characteristics of regulating the mind and calming the four internal organs. This unique view on diagnosis and treatment has profoundly influenced the diagnosis and treatment theories of mental illnesses by later doctors, and is of great significance to the current clinical treatment of such illnesses.