Pneumoperitoneum is an accumulation of fluid in the abdominal cavity. The main causes of pneumoperitoneum are liver disease, portal hypertension, peritoneal disease, kidney disease, and lymphatic system disease. Most patients develop abdominal fluid mainly due to liver diseases, such as cirrhosis or liver tumors that tend to cause abdominal fluid, which is also clinically known as peritoneal fluid, mainly referring to the excessive accumulation of free fluid in the abdominal cavity. If in a pathological state, the amount of fluid may exceed 200ml, commonly in cirrhosis and non-infected hepatocellular carcinoma. Treatment is mainly through abdominal puncture which can extract the fluid from the abdomen, and at the same time can understand the nature of the fluid and the patient’s related inflammation or infection, which is also a means of treatment. During the treatment period, attention should be paid to the diet and the intake of water and salt should be controlled.