Nudge design is a design approach that uses people’s psychological preferences and cognitive limitations to guide people to make choices. The theoretical basis of nudge design mainly comes from psychology and behavioral economics, among which limited rationality theory, cognitive behavior theory, and Fun theory are important theoretical frameworks. This paper summarizes the basic contents of these three theories and their application examples in nudge design. By analyzing the relevant cases of nudge design, the application effects of these three theories in different fields and scenarios are expounded, such as public transportation, environmental protection, health management, education and training, etc., to provide reference and enlightenment for the theory and practice of nudge design.