Abstract: In cyberspace, as a complex social phenomenon, populism is a social trend of thought, a political strategy and a social movement as well. Generally speaking, the action logic of populism in cyberspace follows the law of “social trend of thought → political strategy → social movement”, and its process is shown as “public opinion fermenting → public opinion denouncing → public resentment boiling → network mobilization → network spillover”. In current china, the breeding situation of populism in cyberspace is complex. It is the product of the interaction of social, psychological and political factors. To a certain extent, although populism in cyberspace has the social function of warning, it also has the harm of impacting the mainstream ideology, stirring up the social contradictions, destroying the social order and so on. Therefore, in the foundation of paying attention to social justice and people-centered and starting from the breeding situation of populism in cyberspace, we should follow the logic of technology interruption, system construction, identity construction and root cause governance to effectively control its harm.