Abstract: This study investigates the impact mechanisms and spatial effects of computing infrastructure on the coordinated governance of pollution reduction and carbon mitigation using panel data from Chinese cities. The findings are as follows. First, computing infrastructure significantly promotes the coordinated governance of pollution reduction and carbon mitigation, though an inverted U-shaped nonlinear relationship is identified, indicating a threshold effect in its environmental benefits. Second, spatial econometric analyses based on both geographical distance and economic distance weight matrices reveal that the spatial spillover effects of computing infrastructure on coordinated governance are significant along the geographical proximity dimension but not along the economic similarity dimension. Third, mechanism tests demonstrate that computing infrastructure facilitates coordinated governance through two key pathways, namely promoting green technology innovation and upgrading industrial structure. Further moderation effect analysis indicates that environmental regulation intensity and digital governance capacity primarily moderate the pathway from computing infrastructure to green technology innovation. Fourth, heterogeneity analysis shows that the governance effects of computing infrastructure are more pronounced in non-resource-based cities and megacities. This paper provides empirical evidence for understanding the systematic role of computing infrastructure in environmental governance and offers insights for designing regionally differentiated and coordinated policies for green and low-carbon development.