The public awareness of environmental protection is rising with the development of network technology and the popularization of environmental knowledge. the impact mechanism of public participation in environmental governance in the context of big data in this study was explored by integrating the theory of planned behavior (TPB) and the norm activation model (NAM). The results show that: (1) the external environmental awareness, internal responsibility, social norms as external pressure and private norms as internal driving force all have a positive impact on public participation in environmental governance. (2) environmental attitude affects public participation behavior in environmental governance through the intermediary variable of “subjective norms”, environmental awareness affects public participation in environmental governance by affecting social norms, and responsibility attribution affects public participation in environmental governance by affecting private norms. The subjective norm plays a part of intermediary role in the relationship between environmental attitude and public participation behavior (PPB). (3) government support and media platform are moderating variables between environmental attitude and PPB in environmental governance. Government support can enhance the positive impact of environmental awareness on PPB, and media platform can enhance the positive impact of responsibility attribution on PPB. This is mainly because that it still needs to rely on various resources and opportunities to transform the subjective attitudes and intentions into practical actions.