【Abstract】Summary：Postoperative cognitive dysfunction is complication of the central nervous system after anesthesia, it is common in elderly patients over 65 years. Purpose: In order to facilitate the clinical application, this paper analyzes and summarizes the commonly used diagnostic methods of postoperative cognitive dysfunction. Content: This article briefly describes the postoperative cognitive dysfunction epidemiology and pathogenesis, detailed analysis of postoperative cognitive dysfunction diagnostic criteria and methods, outlines the postoperative cognitive dysfunction. Trend: There is no uniform standard for the diagnosis of postoperative cognitive dysfunction. Further studies are needed to provide better guidance for clinical work.