The amount of fluid released for the first time by laparotomy depends on the purpose, if the released ascites is used for diagnosis and treatment, generally the amount of ascites 300-600ml can clarify the condition. If for therapeutic purpose, the first release of ascites should not be more than 1000 ml, and each subsequent release of ascites by laparotomy should not be more than 3000 ml. A large amount of ascites may cause an increase in the volume of return blood, aggravate the burden on the heart, and complications such as hepatic encephalopathy may occur. During the process of draining ascites, pay attention to observe whether the patient’s vital signs such as blood pressure and heartbeat are stable. If there is abdominal discomfort or a drop in blood pressure or rapid heartbeat, it is recommended to stop putting ascites, and the patient’s safety should be the main concern.