Recently, the relationship between green human resource management (GHRM) and environmental performance has received a lot of attention from scholars. Teaching, training, and research and development carried out in higher education institutions, which are crucial sources for the promotion of sustainability, encourage GHRM. Using signaling theory, this study aimed to deal with the different roles of green training in the Ministry of Education’s corporate environmental performance. The mediation analysis of organizational citizenship behavior towards the environment was considered and the moderation role of perceived organizational support was evaluated. A survey was prepared to analyze the opinions of managers and staff of the Ministry of Education in Iran. After collecting the surveys, 211 complete responses were analyzed and the most important results from these surveys concluded that: (1) the important tools in adopted strategies for green training improve organizational citizenship behavior towards the environment (OCB) and the Ministry of Educations’ environmental performance; (2) the role of OCB in mediating the effects of training on corporate environmental performance (CEP) is essential; (3) perceived organization support (POS) has a moderation role between green training and CEP.