Positive illusions refers to an individual’s positive psychological adaptation, which reflects the individual’s positive grasp of reality and optimistic perception. It is an important research direction in the field of positive psychology. Based on the review and analysis of the existing relevant literature, this paper sorts out the development of positive illusions research, summarizes the connotation and types of positive illusions, explores the role of positive illusions on individual behavior, and introduces the main research areas of current positive illusions. Finally, the existing problems and future research directions are discussed.