More and more studies have paid attention to how cyberbullying victimization leads to adolescents' suicide ideation. The present study explored a new explanation of worldviews or world assumptions through the lens of the shattered assumptions theory. We investigated the associations among cyberbullying victimization, belief in a just world, suicide ideation, self-esteem, and perceived social support. Results drawn from 3322 Chinese adolescents (mean age = 16.64 years, SD = 1.32) indicated a positive correlation between cyberbullying victimization and suicide ideation, which was mediated by belief in a just world. Moreover, self-esteem and perceived social support moderated the negative correlation between cyberbullying victimization and belief in a just world. The findings demonstrated that cyberbullying victimization, as a form of traumatic events, is likely to shatter an individual's world assumption (i.e., belief in just world), which may eventually result in suicide ideation. Surprisingly, for those participants with a higher self-esteem or stronger perceived social support, belief in a just world was more strongly affected by cyberbullying victimization. This paper elaborated on the implications of these findings concerning applications and developments of the shattered assumptions theory.