There are several common reasons for patients to have recurrent fever after appendicitis surgery: a. Gangrene or perforation due to heavy inflammation of the appendix, resulting in serious infection in the abdominal cavity with more pus accumulation, which is not completely removed during surgery, and there is still more fluid and pus residue in the abdominal cavity after surgery, which can cause patients to have recurrent fever and need to strengthen anti-infection treatment to promote faster absorption of pus accumulation thus reducing the symptoms of fever. Second, the appendiceal root is brittle, and after surgery, fecal leakage occurs, and feces in the colon leaks into the abdominal cavity through the appendiceal root, causing serious infection in the abdominal cavity, resulting in acute diffuse peritonitis, and the patient will also experience recurrent chills and high fever, which requires secondary surgical exploration and treatment if necessary. Third, post-operative appendicitis causes purulent infection of the abdominal incision, and fever will also appear. It is necessary to check whether the wound is accompanied by redness, swelling and pain, and if obvious fluctuation is found, it is necessary to open the incision and thoroughly remove fluid and pus accumulation to reduce the symptoms of fever.