This book systematically sorts out and summarizes the basic theories of Chinese medicine and the principles, methods and prescriptions of diagnosis and treatment of diseases in various clinical departments, and makes an incisive exposition on the basic theories of Chinese medicine, especially the theories of mutual root of yin and yang, restraint of five elements, correlation between five internal organs, correlation between qi and blood, and the theory of regulating qi, blood and fire. For example, it is proposed that "local treatment is local treatment, such as a person's heartache, not treating the heart but treating the liver; For example, the disease is above and the treatment is below; For example, the disease is on the right and the cure is on the left; For example, the disease is in the limbs, hands and feet, and the treatment of the abdomen and heart is also biased. It is also pointed out that the methods of treating pericardium from heart disease and kidney from upper jiao to lower jiao have played a great role in the theory of five internal organs in Neijing. This book attaches importance to the flexibility of syndrome differentiation, which is square, small but precise, and large in quantity. It has many unique features, such as "Zhengyi method" to treat lung abscess. Honeysuckle was used until 3009 to play its role in clearing away heat and toxic materials, making the lung golden and abscess disappear; The prescription of "Tongzhi Law" for diarrhea is 909 for Radix Paeoniae Alba and Radix Angelicae Sinensis respectively, which accords with the therapeutic principle that "promoting blood circulation will lead to self-healing of pus".