The rapid rise and wide penetration of environmental, social and governance (ESG) practices have promoted the green transformation of supply chains (SC) and provided opportunities for building sustainable SC. Corporate environmental governance is a vital ESG component that requires leveraging the synergy between enterprises in SC. This study constructs a panel dataset of listed corporates and their suppliers and retailers from 2008 to 2022, and explores the peer effect of SC on corporate green investment (CGI) behavior. The findings show that CGI decisions of suppliers and retailers in SC affects that of core enterprises. Thus, CGI behavior has a peer effect in SC. We prove the validity of the conclusion through some robustness tests. Further examination of the influencing factors shows that environmental information transmission and institutional pressure positively promote the CGI peer effect from environmental and social aspects respectively. This research supplements the literature on the study of sustainable SC, broadens the research boundaries of enterprise sustainable development and ESG performance, and has important implications for promoting SC sustainability.