To explore the influence of upward social comparison on social networking sites on individual well-being, as well as the role of envy and nature connectedness, a questionnaire survey was conducted among 1078 college students. The results indicated: (1) upward social comparison on social networking sites had a significant negative effect on well-being; (2) envy played a mediating role in the relationship between upward social comparison on social networking sites and well-being; and (3) nature connectedness moderated the direct effect of upward social comparison on social networking sites on well-being and the mediating effect of envy. The present study revealed the relationship between upward social comparison on SNSs and well-being and its internal mechanism, providing concrete ways to intervene individual well-being in the Internet era.