This paper extends the concept of psychological ownership to the general natural environment, clarifies the concept of environmental psychological ownership, and analyzes the formation mechanism of environmental psychological ownership from three dimensions. According to the results of structural equation model based on data obtained from the questionnaire survey, pro-environment investment, environmental self-efficacy, and environmental knowledge are all positively associated with the individual’s environmental psychological ownership, among which the correlation between environmental knowledge and environmental psychological ownership is the strongest. In addition, the environmental psychological ownership positively predicts the individual’s pro-environmental intentions. The conclusion of the study can guide how to strengthen the environmental psychological ownership, thus providing a new perspective for pro-environmental behavior intervention.