Based on Norman's three-level theory of emotion-instinct, behavior, and reflection, the article quantifies and analyzes the emotional elements in visual interaction design. Cognitive psychology provides a foundation for studying user behavior and habits for user design. "By comparing the emotional performance and function of visual design and the analysis of the emotional mechanism in interface design, it is concluded that the emotional expression of user interface has two functions: one is to shape and convey the emotional theme of the user interface, and the other is to satisfy the user's unique emotional appeal in different scenarios. The emotional stimulation in the interface can arouse the user's positive emotions and life state. Finally, through actual cases and design practices of sleep products with apps, the three aspects of Norman emotional design, instinct-behavior-reflection, were studied respectively.