With the rapid development and huge progress of surgery, more and more patients choose to undergo surgery. Postoperative delirium is a common complication which has attracted increasing attention. However, the pathogenesis of postoperative delirium remains unclear, and it is still not easy to diagnose the disease. Postoperative delirium has diverse manifestations and is easy to be misdiagnosed, without specific biochemical markers. The treatment of postoperative delirium is still difficult, especially the lack of effective drugs. This paper summarized the diagnosis, pathogenesis, prevention and treatment of postoperative delirium, so as to facilitate future research.