The work aims to analyze the appearance design features of electric vehicles, combining consumer preferences and the need for brand recognition, and improve user satisfaction. Thedesign features of electric vehicle are analyzed, introducing the prototype category theory to study consumer preferences. The shape grammar is parametrized to develop modifiable rule constraints based on the prototype preference model and the requirements of brand recognitionfor changes in design feature curve. Then the concepts, preference factor and brand factor, are proposed to adjust the coordinate point change space of the modification rule, using interactive genetic algorithms to establish a computer aided design system. Finally, the computational fluid dynamics(CFD)analysis method is used to analyze the external flow field and surface pressure of the car shape and then thebody shape is inspected and optimized, finally the design results are compared and evaluated. Theelectric vehicle shape design method based on preference and shape grammar is proposedAnd the prototype preference model is established through the preference survey analysis of young consumers. Combined with the computer-aided design system, the feature level in the prototype preference model is analyzed, the coordinate value of the analysis result is obtained and the relevant feature level is linearly expressed, the ideal low wind resistance body model is established and the specific style is optimized. Taking the Audi brand electric vehicle design as an example, the simulation analysis results of theideal low wind resistance body model established according to the analysis are more satisfactory, and the user satisfaction degree of the design effect was compared and evaluated, which verified the feasibility of the method. This method can effectively improve users' satisfaction with the appearance design of electric vehicles.