When consumers perceive that companies are engaging in greenwashing, this often has many negative impacts on the company, industry, and society. Based on the psychological contract theory, this study constructs a moderated mediation model in an attempt to demonstrate that consumers’ greenwashing perception influences their green purchasing intentions and, more importantly, that this influence is mediated by consumers’ perceived betrayal and moderated by their sense of environmental responsibility. An online questionnaire was used to distribute 220 questionnaires and regression analysis was conducted using SPSS24.0 and Amos24.0 to test the hypothesis. The results show that consumers’ greenwashing perception negatively influences consumers’ green purchasing intentions, that perceived betrayal plays a partially mediating role in this influence relationship, and that environmental responsibility reinforces the negative influence of greenwashing perception on green purchasing intentions. This paper enriches the study of the mechanisms of individual consumer psychological effects after consumers perceive corporate greenwashing behaviour, which is of great value to both corporate performance and the sustainable development of the social environment.