Cirrhosis can cause pulmonary arteriovenous fistulae, not necessarily diffusely. Cirrhosis is primarily a change in the normal structure of the liver due to massive necrosis of hepatocytes, fibrinoid proliferation, and pseudolobule formation. This results in diminished inactivation of estrogen and microcapillary dilatation. Clinically, spider nevi and pulmonary arteriovenous fistulas are seen. Pulmonary arteriovenous fistulas can be subdivided into simple, complex and diffuse types. Cirrhosis can cause pulmonary arteriovenous fistula clinically manifested as cyanosis, pestle finger. Especially after activity shortness of breath, cyanosis obvious. The mechanism is mainly due to the direct shunt from the pulmonary artery to the pulmonary vein, which can make the venous blood in the pulmonary artery directly shunt into the pulmonary vein without the gas exchange of the alveoli, and the patient has obvious cyanosis, hypoxemia, and it is difficult to correct with oxygen. When there is a pulmonary arteriovenous fistula caused by cirrhosis, it should be treated according to the etiology of cirrhosis, and at the same time actively treat the complications. Effective relief of hypoxia symptoms, etc. Cirrhosis patients all need to actively cooperate with doctors for treatment to avoid serious complications.