为了解决流量成本攀升导致中小商家萎缩与平台生态失衡的现实问题，基于平台生态系统理论，构建“平台-头部商家-中小商家”三方多主体竞合仿真模型，探讨流量分配策略对平台利润与生态的影响效果及作用机制，并以现实企业案例进行验证。研究表明，提高流量分配策略逐利性可提升平台利润，但会导致生态恶化，间接引起平台利润下滑，且平台流量变现对中小商家的影响存在“双刃剑”效应；平台保留适当比例的自然流量可为中小商家提供保障，同时提升付费流量竞争水平可增加平台收益，实现利润、生态与社会责任的协同优化。

To address the real-world problem of the decline of small and medium-sized merchants and platform ecosystem imbalance caused by rising traffic costs, this study draws on platform ecosystem theory to develop a multi-agent coopetition simulation model involving the platform, leading merchants, and small and medium-sized merchants. It examines how traffic allocation strategies affect platform profits and ecosystem health, as well as the underlying mechanisms, and validates the findings through real-world business cases. The results indicate that increasing the profit orientation of traffic allocation strategies may enhance platform profits; however, it deteriorates ecosystem health, inflates average product prices, and causes user attrition, indirectly undermining profitability. Furthermore, platform traffic monetization exerts a dual-edged effect on small and medium-sized merchants. Maintaining an appropriate proportion of organic traffic can safeguard the participation of small and medium-sized merchants while intensifying paid-traffic competition can increase platform revenue, thereby achieving synergistic optimization of profitability, ecosystem health, and social responsibility.