Acute appendicitis is the most common surgical emergency abdomen. Currently, the majority of patients are able to seek early medical attention, early diagnosis and early surgery, and receive good treatment results. However, clinicians still encounter problems in the diagnosis of this disease from time to time. The diagnosis of acute appendicitis is an empirical clinical diagnosis, and auxiliary imaging is helpful but not necessary for the diagnosis of acute appendicitis, especially periappendiceal abscess. The clinical diagnosis is based on the following 3 points: (1) Metastatic right lower abdominal pain: Metastatic abdominal pain is an important feature of acute appendicitis. However, it should be noted that 20-30% of patients start with right lower abdominal pain at the onset. (2) Fixed pressure points and different degrees of peritoneal irritation signs in the right lower abdomen. (3) Elevated white blood cell count and neutrophil ratio. The clinical misdiagnosis rate of acute appendicitis is still high, with domestic statistics of 4%-5% and foreign reports of up to 30%. There are many diseases that need to be differentiated from appendicitis, among which the following dozen diseases are the main ones. (1) Diseases that need to be differentiated from medical emergency abdomen: 1 right lower pneumonia and pleurisy. 2 acute mesenteric lymphadenitis. 3 limited ileitis. Internal acute abdominal disease is often preceded by fever and followed by abdominal pain, which may be preceded by headache, aching limbs and loss of appetite. (2) Diseases that need to be differentiated from obstetrical and gynecological emergencies: 1 right-sided tubal pregnancy: ectopic pregnancy often has a history of menopause and early pregnancy and can be preceded by vaginal bleeding. 2 ovarian cyst torsion: but this disease often has a history of pelvic mass and sudden onset, paroxysmal colic may be accompanied by mild shock symptoms. The cystic mass is palpable and painful on gynecologic examination, and the presence of a cystic mass in the right lower abdomen is confirmed by abdominal ultrasound.3 Ovarian follicular rupture: It occurs mostly in unmarried young women, often two weeks after menstruation, and causes right lower abdominal pain due to intra-abdominal bleeding. The local signs in the right lower abdomen are mild, and diagnostic laparotomy can extract bloody exudate.4 Acute adnexitis: tubal inflammation mostly occurs in married women with a history of excessive leukorrhea and the onset of multiple menstrual periods before menarche; although there is right lower abdominal pain, there is no typical metastasis, and the abdominal pressure site is low, almost near the pubic bone; gynecologic examination reveals purulent vaginal exudate, significant tenderness on both sides of the uterus, and tenderness in the right adnexa The gynecological examination shows purulent vaginal exudate, painful palpation on both sides of the uterus, and painful palpation in the right adnexa. (3) Diseases that need to be differentiated from acute surgical abdomen: 1. Gastroduodenal ulcer perforation: the overflowing gastrointestinal contents of the perforation flow into the right lower abdomen along the paracolic sulcus of the ascending colon, which can be easily mistaken for metastatic right lower abdominal pain of acute appendicitis. The disease has a history of chronic ulcers, and the onset of the disease is often preceded by overeating and drinking, with sudden onset and severe abdominal pain. During physical examination, the abdominal wall is seen to be plank-like, and the peritoneal irritation sign is most obvious under the fenestra; free gas is visible under the diaphragm on abdominal fluoroscopy, and upper gastrointestinal fluid can be extracted by diagnostic laparotomy.2 Acute cholecystitis and cholelithiasis: Acute cholecystitis may present with a positive Murphy’s sign, and even an enlarged gallbladder may be palpated, and emergency abdominal ultrasound may show gallbladder enlargement and stone sound shadow.3 Acute meckel diverticulitis or perforation: When clinical Diagnosis of appendicitis without surgery in which the appendix is basically normal in appearance, due to careful examination of the terminal ileum to 1 m, so as not to miss the inflamed diverticulum.4 Right ureteral stone: ureteral stone attacks into severe colic, unbearable, pain along the ureter to the vulva, inner thighs dispersion. Abdominal plain film sometimes shows positive stones in the urinary tract, while urine routine has a large number of red blood cells. If the patient has persistent right lower abdominal pain that cannot be explained by other diagnoses while acute appendicitis cannot be excluded, close observation or timely surgical exploration should be performed according to the condition.