[Purpose/significance] To clarify the relationship between users, behaviors and competitive information dissemination in infodemic, the paper reveals the laws of infodemic generation and dissemination, and provides theoret? ical support for the formulation of infodemic intervention strategies.[Method/process] Supported by complex network theory and Sina Weibo platform as a reference, the correlation mechanism between users, information and behaviors was extracted, and the Logistic model and behavioral game model were comprehensively used to establish a competitive information dissemination model for infodemic. The model is validated by computational experiments. [Result/conclu? sion] The research shows that users' originality, forwarding, and commenting behaviors will affect users' susceptibility to infodemic and the competitive dissemination of true and false information in infodemic. Rebuilding the order of user behavior and guiding users to generate high-quality true information is an effective strategy to help users avoid the im? pact of infodemic.