Abstract: This study utilizes the evolutionary game theory to construct a tripartite game model among platform owners, complementors, and users within the digital platform ecosystem. Through simulation experiments, the equilibrium points were validated, and the states of each party corresponding to different equilibrium points were explored, thereby elucidating the multi-agent strategic interaction logic. Additionally, the dynamic evolution of equilibrium states was analyzed using a three-dimensional dynamical system, and the evolution paths of the dynamic equations and the stability of their equilibrium points were demonstrated during the modeling process. Based on the simulation results, the conclusions are as follows：(1) During the unstable development phase of the platform, the platform, complementors, and users tend to adopt strategies of balanced resource allocation, multi-homing, and non-purchase, respectively. (2) In the platform improvement phase, the strategic game between the platform and complementors becomes prominent. A high proportion of resource allocation by the platform incentivizes complementors to provide high resource feedback, and complementors adopting a customization strategy encourage the platform to allocate more resources to them.(3) During the platform maturity phase, increasing resource investment by platform owners, appropriately reducing product pricing, and strengthening market regulation will increase the probability of users choosing to purchase.(4) The dynamic evolution of the digital platform ecosystem is highly sensitive to various parameters, manifested as the equilibrium point dynamically evolving with changes in parameters. This indicates that strategic interactions among entities are significant and easily influenced by the strategic decisions of other entities. This study expands the research focus of platform governance from a single-agent perspective to the strategic interactions among multiple agents, and achieves a transition of the dynamic model from an internal/equilibrium model to an external/balance model. It reveals the core governance logic of the digital platform ecosystem, enriches the existing platform governance theory, and provides profound practical insights.