BACKGROUND: Prior work suggests that problematic short video use was associated with adverse psychological, physiological, and educational outcomes. With the prevailing of short video platforms, the potential relationships between this problematic behavior and suicidal ideation and self-injurious behaviors have yet to be thoroughly examined. Besides, considering the potential dual nature of problematic short video use, particularly its positive aspects, a potential mechanism may exist linking such problematic behavior to SI and SIBs, ultimately driving individuals towards extreme outcomes. Nevertheless, such mediation paths have not been rigorously examined. Thus, the current study aimed to investigate their relationships and delve into the underlying mechanism, specifically identifying potential mediators between sleep disturbance and depression. METHODS: A quantitative cross-sectional study design was employed to model data derived from a large sample of first- and second-year university students residing in mainland China (N = 1,099; Mage = 19.80 years; 51.7% male). RESULTS: Results showed that problematic short video use has a dual impact on SI and SIBs. On the one hand, problematic short video use was directly related to the decreased risk of suicidal ideation, attempts, and NSSI. On the other hand, such problematic behavior was indirectly associated with the increased risk of NSSI through sleep disturbance, and it indirectly related to the elevated risk of suicidal ideation, attempts, and NSSI through depression. Besides, on the whole, problematic short video use was positively associated with NSSI but not suicidal ideation and attempts. CONCLUSIONS: These findings indicated that problematic short video use had a dual impact on SI and SIBs. Consequently, it is paramount to comprehend the genuine magnitude of the influence that such problematic behavior holds over these intricate psychological conditions.