Head-low-foot-high position is suitable for the following situations: I. Patients with lung infection and inability to discharge sputum can adopt head-low-foot-high position to promote the drainage of sputum in the bronchi, which is conducive to faster control of lung inflammation. Patients with acute appendicitis and bilateral inguinal hernia need to undergo laparoscopic surgery. The head-low-foot-high position can make the free small intestine in the abdominal cavity slide into the upper abdomen due to gravity, fully reveal the surgical area, avoid damage to the small intestine intestinal tube, facilitate faster surgery and reduce surgical complications. Third, in patients with rectal malignant tumor, the procedure requires the clearance of lymph nodes in the root of the inferior mesenteric artery. The head low and foot high position can fully reveal the area of the inferior mesenteric artery, so that the local lymph nodes can be completely cleared and the purpose of surgical cure can be achieved.