Acute abdomen in the elderly is a frequently-occurring disease characterized by acute abdominal pain and accompanied by a series of manifestations such as acute systemic symptoms. It has the characteristics of rapid onset, rapid development, severe condition, multiple changes and complex etiology. It involves inflammation, obstruction, bleeding, circulatory disorders, perforation, infection and poisoning, fluid disorders and shock in multiple organs of the digestive, urinary and reproductive systems. Due to the decline in organ function, reduced reaction ability and atypical clinical manifestations in the elderly, they are prone to misdiagnosis and mistreatment. Therefore, for acute abdomen in the elderly, it is necessary to master its characteristics and the law of disease changes in order to achieve early correct diagnosis and timely and effective treatment.