Online deviant behavior is a series of maladaptive behaviors that may have adverse effects on the physical and mental health of others and adolescents in the Internet environment. Previous studies have paid more attention to the risk factors of adolescent online deviant behavior. However, its protective factors and psychological mechanisms remain unclear. Thus, this study explored the protective effect of virtuous personality trait on adolescents' online deviant behavior and its psychological mechanism. A total of 851 Chinese college students anonymously completed a series of questionnaires about virtuous personality trait, moral disengagement, perspective taking, and online deviant behavior. The findings showed the following: (1) Virtuous personality trait was negatively correlated with online deviant behavior. (2) Moral disengagement mediated the relationship between virtuous personality trait and online deviant behavior. (3) Perspective taking moderated the first half stage of the mediation model in which college students' virtuous personality trait influences online deviant behavior via moral disengagement. (4) A moderated moderated-mediation analysis found that gender moderated the moderating effect of perspective taking on the relationship between virtuous personality trait and moral disengagement. This study is helpful to demonstrate the protective effect and psychological mechanism of virtuous personality trait on online deviant behavior. Some theoretical and practical significance and limitations were also analyzed and discussed.