In recent years,the development of artificial intelligence(AI)is gradually changing the traditional medical industry.Machine learning,as the mainstream of artificial intelligence technology,is increasingly applied to analyze complex data in medical research.It provides convenience for disease diagnosis,risk assessment and diagnosis and treatment decision making.This paper reviews the application of machine learning algorithms in postoperative delirium at home and abroad,in order to provide a new idea for the construction of postoperative delirium prediction model and a new basis for early clinical evaluation of postoperative delirium.