Abstract: To tackle issues such as collusion and rent-seeking between manufacturers and inspectors or third-party testing agencies, as well as insufficient regulation in e-commerce platform sales, this study develops a tripartite evolutionary game model involving the platform, inspectors, and manufacturers. By analyzing the influencing factors of the system evolution, the study explores the behavior and evolutionary stable strategies of all parties, with the aim of providing insights for the sustainable and high-quality development of the e-commerce supply chain. Results show that: 1) when the e-commerce platform can achieve high net profits from product sales with low government penalties for substandard products, it tends to adopt a lenient regulatory strategy, tolerating manufacturers to produce substandard products and acquiescing in rent-seeking and collusion by inspectors. 2) Regardless of the level of regulatory intensity on the e-commerce platform, as long as producing substandard products or accepting rent-seeking yields significant profits, manufacturers and inspectors are inclined to adopt a collusion strategy to pursue short-term gains. Based on these findings, the study proposes feasible recommendations to promote standardized operations within the e-commerce supply chain, offering strategic guidance for the establishment of a robust and sustainable e-commerce ecosystem.