| Taking "metal crystal" as the carrier of chemical knowledge,this study combined quasiexperimental research with qualitative research to explore the correlation variables,effective thresholds and optimization paths of visual emotional design in multimedia video.The following conclusions are formed:（1）At the non-cognitive level,visual emotional design and dynamic/static presentation had no significant effect on learners’ positive emotions,but there was a learner effect.The results of "gender" perspective analysis showed that there was gender difference in the induction effect of dynamic/static presentation on learners’ positive emotions.When the multimedia video was static,Girls’ positive emotions were significantly lower than boys’.The results of "academic level" perspective analysis showed that when the multimedia video was designed with positive visual emotions and dynamic,the positive emotions of learners with low academic level were significantly higher than those of learners with high academic level.（2）At the cognitive level,visual emotional design can significantly improve the relevant cognitive load,while dynamic/static presentation can significantly reduce the internal and external cognitive load.For spatial knowledge learning,visual emotional design and dynamic/static presentation can significantly improve spatial understanding performance.In addition,the results of interaction analysis show that positive visual emotional design can significantly reduce learners’ internal and external cognitive load only when it is combined with dynamic presentation.（3）Of cognition and cognitive level correlation analysis results show that the multimedia video induced by positive emotions,can decrease the difficulty of learners perception of knowledge in the theme to promote the understanding of knowledge in topic organization and presentation,and then put more cognitive resources to build the information components,the structure of the relationship between the formation of a more solid knowledge schemata.However,the mediating path of "visual emotional design → cognitive load → spatial knowledge learning effect" is not significant,which may be affected by the complexity of the environment.（4）Based on the case study,the optimization strategies of visual emotional design can be summarized as follows:（1）Focusing on the change of audience group,using "learning cases" to enhance its advantages and avoid its disadvantages;（2）Pay attention to the appropriateness of knowledge theme,avoid attaching decorative picture labels to emotional design;（3）Pay attention to all-round personification and lead learners to travel micro-world with knowledge subject action. |
