The patient may use laparotomy to extract peritoneal fluid after the development of peritoneal fluid. The specific steps are as follows: 1, according to the condition and needs, the patient can be placed in a flat, semi-recumbent or slightly left lateral position to make the patient as comfortable as possible and empty the urine; 2, choose a suitable puncture site, a few effusions or encapsulated effusions can be punctured and positioned under the guidance of ultrasound; 3, wear sterile gloves, routine disinfection of the puncture site and cover the hole towel, use 2% lidocaine from the skin to the peritoneal wall layer to do local anesthesia; 4, the operator uses The operator fixes the skin of the puncture site with the left hand, and the right hand holds a needle through the anesthesia into the abdominal wall to extract ascites, and puts the extracted fluid into a test tube for examination. When doing diagnostic puncture, it can be done directly with a 20 ml or 50 ml syringe and an appropriate needle. When releasing a large amount of fluid, use an 8- or 9-gauge needle and connect a rubber tube to the needle base, then clip the infusion clamp to adjust the speed and introduce the ascites into the container for measurement and laboratory examination. The fluid should not be released too much or too fast, usually not more than 3000 ml at a time, and after the release of fluid, the puncture needle should be removed, covered with gauze and bandaged. After the operation, the patient was asked to rest flat for 2 hours, avoiding lying on the puncture side, and blood pressure was measured and observed for any changes in the condition.