Abstract With the large-scale application of computational propaganda, disinformation campaigns have emerged globally in response to the logic of “post-truth” politics. Organized disinformation campaigns operate frequently on overseas social media platforms, with China often being the target. In order to understand the dissemination mechanisms of such disinformation campaigns, the study found that the dissemination of disinformation became a key strategy for the campaign’s emotional mobilization. The main subjects of disinformation have formed an international communication matrix, creating and spreading all kinds of disinformation on a large scale. The “coalition of protesters” is based on the shared emotional experience evoked by disinformation and characterized by the act of spreading disinformation. Then, the widespread dissemination of the corresponding emotions leads to different perceptions of the “target,” thus prompting protesters to adopt different types of collective action. This mechanism of emotional mobilization shows that facts are “too big to know,” which exacerbates confirmation bias and provides more space for the spread of disinformation. The strong emotions embedded in disinformation contributed to the completion of the protesters’ imagination of community, and emotions became the dominant factor in coalescing the group and providing motivational support for collective action.