Based on twelve typical cases of value co-creation between platform-based cloud service providers and users, the antecedent conditions and operational mechanisms of value co-creation between the two parties were systematically analyzed, and an integrated model of value co-creation was constructed for platform-based cloud service providers and users relying on knowledge-based dynamic capabilities (KBDCs) under the influence of group dynamics. The findings are as follows. The value co-creation process between platform-based cloud service providers and users evolves through three stages: value assessment, value bridging, and value aggregation. KBDCs constitute the key antecedents driving value co-creation, with knowledge search dynamic capabilities, among which knowledge search dynamic capabilities, knowledge integration dynamic capabilities, and knowledge development dynamic capabilities exert key roles in the assessment, bridging, and aggregation stages of value co-creation respectively. Group dynamics serve as boundary conditions affecting the impact of knowledge-based dynamic capabilities on value co-creation, whereby congruent group cognition and proactive group actions enhance the cohesion of value co-creation between platform-based cloud service providers and users. The conclusions enrich the theoretical system of value co-creation between cloud service providers and users, refine the conceptual connotations of knowledge-based dynamic capabilities, expand the application boundaries of group dynamics theory, and provide practical guidance for facilitating value co-creation in platform-based cloud service contexts.