Peritoneal fluid puncture has a certain degree of pain, clinically do peritoneal fluid puncture mainly includes two kinds of situations: First, diagnostic peritoneal puncture, suspected of abdominal bleeding or ascites, then usually choose to use a 5mL syringe, with a 7-gauge needle in the position of the anti-McGrath’s point of the puncture, due to the needle is relatively small, relatively speaking, puncture pain is relatively small. Secondly, if there is fluid in the abdominal cavity with infection, then it is necessary to puncture and place a tube under ultrasound guidance. The diameter of the puncture tube is usually more than 5mm, and it needs to be placed under ultrasound guidance and local anesthesia, otherwise, the pain of the 5mm puncture tube through the skin of the abdominal wall will be more severe. Both diagnostic paracentesis and paracentesis are invasive and therefore painful.