Abstract: To tackle issues such as collusion and rent-seeking between manufacturers and inspectors or third-party testing agencies during the sales process on e-commerce platforms, and to address the lack of adequate regulation, this study develops a tripartite evolutionary game model that encompasses the platform, inspectors, and manufacturers. By analyzing the influencing factors of the system's evolution, the study explores the behaviors and evolutionary stable strategies of the various parties involved, with the aim of providing recommendations for the sustainable and high-quality development of the e-commerce supply chain. The research reveals that: (1) when the e-commerce platform can achieve high net profits from selling a certain product and the government penalties for substandard products entering the market are relatively minor, the platform tends to adopt a lenient regulatory approach, tolerating manufacturers to produce substandard products and acquiescing to inspectors' participation in rent-seeking and collusion; (2) regardless of the level of regulatory intensity on the e-commerce platform, as long as producing substandard products or accepting rent-seeking promises significant profits, manufacturers and inspectors are inclined to opt for a collusion strategy to secure short-term gains. In light of these findings, the study proposes actionable recommendations to foster standardized operations within the e-commerce supply chain, offering strategic guidance for the establishment of a robust and sustainable e-commerce ecosystem.