With the upsurge of "emotional storm" in the field of organizational behavior, the studies on individual emotions in organizational context are rising. Especially the relationship between emotions and knowledge innovation has attracted much attention by scholars. In particular, individual emotions may exert great effect on knowledge innovation whereas the mechanism is still unclear. Based on the emotional event theory, this paper constructs a model which explores the interaction of positive and negative emotions with individual knowledge innovation. Based on questionnaire data analysis, the results show that knowledge sharing partly mediate the relationship between positive emotion and knowledge innovation as well as the relationship between negative emotion and knowledge innovation; team trust accentuates the relationship between positive emotion and knowledge innovation as well as the relationship between negative emotion and knowledge innovation. The above findings are helpful to clarify the impact mechanism of emotions on knowledge innovation.