Appendicitis can be diagnosed and confirmed with the help of a CT scan of the abdomen. Appendicitis is a bacterial infection of the appendix, obstruction of the lumen of the appendix, etc., leading to an inflammatory response in the appendix. Clinical confirmation of the diagnosis relies on history, clinical symptoms, signs and imaging. Clinical symptoms include typical metastatic right lower abdominal pain, fever, gastrointestinal reaction, etc. Signs include right lower abdominal tenderness, positive peritoneal irritation sign, etc. Imaging tests include abdominal plain radiographs that reveal a dilated cecum or a fluid-gas plane, and ultrasound occurs with an enlarged appendix. Abdominal CT is more sensitive and can detect localized swelling and thickening of the appendix, the presence of inflammatory exudates around the appendix, appendiceal fecaliths, effusion, pus and gas, etc. It can also detect periappendiceal abscess, which, in combination with the patient’s typical clinical symptoms and signs, helps to confirm the diagnosis of appendicitis. The diagnosis of appendicitis needs to be combined with a variety of clinical data, comprehensive diagnosis, CT can help to confirm the diagnosis of appendicitis, it is recommended to consult a doctor in a timely manner, standardized treatment.