With the increasingly severe global climate change and environmental issues, low-carbon green development has become an urgent global necessity. It is focused on green event activities,the 2022 Beijing Winter Olympics is used as the experimental backdrop. Event-related potential (ERP) technology is employed to analyze brainwave data from 35 participants, combined with Bayesian learning theory, to study changes in participants' decision-making under different informational backgrounds (no background information, viewing promotional images, watching environmental videos), aiming to reveal the neural cognitive mechanisms behind the "intention-decision" inconsistency in green behavior decisions. This methodology not only aids in identifying consumers with a low-carbon environmental awareness but also offers a new perspective on understanding the decision-making mechanisms of the general audience in green event activities. The results are significant for promoting sustainable development of green events and deepening the understanding of environmental behaviors, potentially providing a scientific basis for green marketing strategies and environmental policy formulation.