<p>Optimizing supply chain configuration has become a proactive strategy for businesses to mitigate external shocks. Utilizing panel data from Chinese A-share listed companies from 2012 to 2021, this study empirically investigates the impact of environmental taxes on enterprise supply chain configuration within a theoretical framework of operational risk and legitimacy mechanisms. The findings indicate that environmental taxes effectively encourage a shift in enterprise supply chain configuration from centralization to diversification. Mechanism analysis indicates that environmental taxes promote the diversification transformation of supply chain configuration through the mechanism of operational risk and legitimization. Furthermore, the drive feature analysis shows that the supply chain positional advantage weakens the influence of environmental taxes on the concentration of supply chain configuration. Driving direction analysis indicates that environmental protection tax mainly drives downstream supply chain configuration diversification transformation. Additionally, boundary condition analysis demonstrates that environmental taxes are more conducive to promoting the transformation of supply chain configuration diversification for enterprises in low-competition markets. Environmental taxes exert a greater impact on supply chain configuration diversification for mature-stage enterprises and heavily polluting enterprises. This study provides empirical evidence for improving environmental policy-making and optimizing supply chain configuration, thus contributing to the theoretical understanding of enhancing enterprise supply chain security.</p>