<p>Supply chain digitalization has emerged as a crucial driver for enterprises seeking environmental advantages. This study aims to explore the impact of technical systems (e.g., information technology (IT) and process integration) on supplier and customer digitalization, which leads to environmental performance, as well as the moderating effects of social systems (e.g., contracts and mutual trust) in the relationship between integration and digitalization. By using data from 150 listed manufacturing firms in China, this study finds that both IT and process integration are positively related to supplier and customer digitalization. On the supplier side, contracts strengthen the positive effect of process integration on supplier digitalization but weaken the impact of IT integration, while on the customer side, mutual trust has no significant moderating effect on the relationship between IT integration and customer digitalization but strengthens the positive effect of process integration. Moreover, supplier digitalization is positively related to environmental performance, while customer digitalization does not. This study enriches the literature regarding how to enhance supply chain digitalization by involving technical and social systems on the upstream and downstream sides, offering insights into how firms can leverage these mechanisms to achieve environmental benefits.</p>