Objective: To provide longitudinal evidence for interventions in suicidal behavior among college students, this study explored the mechanisms underlying the relationship between cyberbully. Methods: Based on the general strain theory, 558 college students from Beijing and Xi an were followed up 2 times(T1 and T2) by using the Cyberbullying Questionnaire, Beck Scale for Suicide Ideation and Center for Epidemiological Survey Depression Scale(CES-D). Results: T1 cyberbully could positively predict depression and suicidal ideation among college students at T2( β =0.06, 0.15, P <0.01), and depression at T1 could positively predict suicidal ideation among college students at T2( β =0.29, P <0.01). The mediation effect revealed that depression at T1 could mediate the relationship between cyberbully and suicidal ideation. Compared to boys, girls were likely to be affected by cyberbully and resulted in depression and suicidal ideation. Conclusion Findings contribute to the prespective causal relation between cyberbullying and suicidal ideation among college students and provide the longitudinal evidence for intervention of suicidal ideation.