Residents' pro-environmental behavior (PEB) is vital for solving environmental pollution. This paper uses a micro sample of 10993 respondents from the Chinese General Social Survey. Propensity score matching was used to assess the effect of Internet access on residents' PEB, and the study finds a significant positive impact on private-sphere PEB and public-sphere PEB. This fundamental conclusion still holds after utilizing the instrumental variable method, changing the dependent variable, core explanatory variable, and the econometric model. Heterogeneous analysis finds that Internet access has a more significant positive impact on private-sphere PEB for elderly, women, low educated and rural residents. Internet access has a more significant positive impact on public-sphere PEB for the middle-aged, women, higher educated, and urban residents. The mediating test suggests that Internet access promotes residents' PEB and raises the overall level of residents' environmental awareness through the mediating factor of residents' PEB. This paper provides the theoretical and empirical basis that Internet technology can promote PEB at the microlevel, which emphasizes the positive impact of information and communications technology on eco-environmental improvement.