Abstract: In the all-media era, a new public opinion arena is being shaped, and social emotions have become an important source of power in triggering mass events. Analysing the mechanism of emotions in online mass events, it is found that emotions can strengthen individual attention, trigger group resonance, and reach social consensus. Through the correlation construction of the core concepts, the emotional communication of online mass events presents a dynamic process of arousal, infection, outburst, and fading of the evolutionary logic. According to Gross’s process model of emotional adjustment, multiple subjects can adopt collaborative governance strategies according to the logic of emotional evolution, and can effectively channel social emotions from four aspects: contextual modification, cognitive change, attention allocation and response adjustment.