Objective: Online aggression (OA) in Chinese university students is a public health concern. Drawing on the general aggression model (GAM), this study examines the extent to which nonviolent and violent stressful life events predict OA through altering moral cognition (i.e., moral disengagement). It also examines whether the two types of stressful life events interactively predict moral disengagement and whether violent stressful life events moderate the link between moral disengagement and OA. Method: Participants were 569 Chinese university students (M age = 21.94 years, 42.5% males). They participated in a three-wave study, with 3-month spanning each wave, to self-report nonviolent stressful life events at Time 1 (T1), violent stressful life events and moral disengagement at T1 and Time 2 (T2), and OA at T1 and Time 3. Results: Results of path analysis showed that after controlling for the baseline levels of respective variables, T2 moral disengagement mediated the associations between T1 violent, but not nonviolent, stressful life events and Time 3 OA. The interactive effect between the two types of stressful life events at T1 on moral disengagement at T2 was insignificant; neither was the interactive effect between T2 moral disengagement and T2 violent stressful life events on Time 3 OA. The significance of results did not change after adjusting students' gender, age, and family socioeconomic status. Conclusion: These findings support the utility of GAM in explaining how OA develops in Chinese young people, implying that some situational inputs appear more important than others in these developmental processes. The results also shed light on strategies to prevent Chinese university students' OA.