With the development of the times, games, which is the basis of entertainment medium, has gradually become the tool of learning for human beings and finally promote the development of serious games. As we know that the interactive experience and aesthetic experience of games are all obtained from game icons. As the communication bridge between players and games, the functional game icons in serious games have evolved from single symbols to diversified styles icons.  With the experiment method like semantic differential and similarity computation, this paper has acquired functional icons of high matching quality and recreated them with emotional design. The case study presented in this thesis demonstrated that in a multitude of serious games, functional icons had suffered the problems of lack of interaction and difference, unbalanced unity and high similarity through comparing the cognitive level experiment of different style icons and the preference experiment of different cognitive styles. This case studies the cognition of functional icons and the types of icons preferred by different cognitive styles. In addition, different styles of functional icons have different cognitive effects, while different cognitive styles have different cognitive functions and preferences. In this case, it was found that the cognitive ergonomics of different styles of functional icons differed. For users familiar with the game, the cognitive ergonomics of flat icons were higher than that of anthropomorphic icons. The cognitive ergonomics of icons with low abstraction level was higher than that of icons with high abstraction level. Meanwhile, the cognitive efficacy and preference of different cognitive styles for different styles of functional icons are different and it is more obvious that intuiting cognitive style users prefer anthropomorphic icons. Sequential cognitive style users have higher cognitive efficacy for anthropomorphic icons than flat icons. The global cognitive style users prefer anthropomorphic icons for icons with high abstraction levels. Therefore, the design of functional icons for serious games should consider the difference in users' cognitive styles because cognitive styles can be used as an entry point for the balance between the serious part and the game part of serious games. Personalized icon design can be designed for different cognitive styles users by combining their preferences for icons, so as to increase users' interest in serious games. The symbolic icons can also be used to let players quickly understand the meaning of the game, so as to improve the learning efficiency of serious games for people with different cognitive styles. / <p>Det finns övrigt digitalt material (t.ex. film-, bild- eller ljudfiler) eller modeller/artefakter tillhörande examensarbetet som ska skickas till arkivet. / There are other digital material (eg film, image or audio files) or models/artifacts that belongs to the thesis and need to be archived. </p>