Acute mesenteric ischemia (AMI) is insidious in the early stage of the disease, and once ischemia reaches the late stage, irreversible intestinal necrosis and even multiple system organ failure occur, ultimately leading to death. Early diagnosis and intervention are the key to improving the outcome of AMI. Intensive care unit (ICU) patients mostly present with non-occlusive mesenteric ischemia (NOMI) due to hypoperfusion. This article reviews the high risk factors, clinical manifestations, biomarkers, and imaging examinations of AMI in order to provide ideas for clinicians in the early identification of this disease.