[Purpose/Significance] With the growing maturity and proliferation of AIGC, the production and dissemination of a large amount of homogenized content will threaten the quality and diversity of the Internet digital content ecosystem, leaving users trapped in an information cocoon that may cause social disruption. Studying the game relationship between platform incentive policies and creator content production can help solve the problem of homogenization in platform content production. [Method/Process] This article derived the Lotka Volterra Logistic dynamic model through evolutionary game analysis, describing the evolution law of the platform's mixed strategy combination between "traffic incentive" and "quality incentive", and the creator's mixed strategy combination between "high quality" and "low quality". Through simulation, it explored the impact of factors such as creator production cost, platform incentive cost, and content domain homogenization on the platform's content ecology evolution mode. [Result/Conclusion] The evolution of platform content ecology generally follows a periodic oscillation and replacement pattern, and the three modes of sustainable development of platform content ecology are "investment driven", "hotspot driven", and "innovation driven". This article provides a reference framework for the platform's content ecology strategy, pointing out that digital content platforms should choose appropriate development models, promote content ecology metabolism according to cyclical laws, and strive to reduce the production costs of creators and the incentive costs of the platform to eliminate development bottlenecks.