The indications for peritoneal fluid puncture are as follows: 1. Diagnostic puncture, new onset of ascites. The ascites test can assist in clarifying the etiology, identifying exudate and leaky fluid, detecting cancer cells, or suspecting spontaneous or secondary bacterial peritonitis; 2. Therapeutic puncture: dyspnea due to massive ascites, abdominal pain and increased abdominal pressure due to ascites, infectious and cancerous ascites, cirrhosis without infection, or massive intractable ascites. Precautions for laparotomy: observe the patient closely during the operation, if there is dizziness, palpitation, nausea, shortness of breath, increased pulse rate and pallor, etc., the operation should be stopped immediately and appropriate treatment should be carried out. If the outflow is not smooth, the puncture needle can be moved slightly or the position can be changed slightly; after the operation, the patient should be asked to lie down and the puncture hole should be located above to avoid the continual leakage of ascites; attention should be paid to the aseptic operation to prevent abdominal infection; abdominal circumference, pulse, blood pressure and abdominal signs should be measured before and after the fluid release to observe the changes of the condition; after obtaining the specimen if the ascites is bloody, suction or fluid release should be stopped.