In the dual context of the continued growth of the Chinese need for uniqueness and the popularity of Internet use among Chinese youth, this study examined the relationship between need for uniqueness and problematic Internet use and its mechanism (the multiple mediating effects of stress and ego depletion). Using a three-wave longitudinal design, a total of 470 Chinese adolescents (girls = 237, Mage = 13.13, SD = 0.67) were tested by the Need for Uniqueness Scale, Depression-Anxiety-Stress Scale (DASS-21), Ego Depletion Scale and Problematic Internet Use Scale. The results showed that: (1) Need for uniqueness, stress, ego depletion and problematic Internet use were positively correlated with each other. (2) Mediation model test indicates that stress had a significant mediating effect between need for uniqueness and problematic Internet use. The chain mediating effect of stress and ego depletion was also significant. However, ego depletion cannot mediate the relationship between need for uniqueness and problematic Internet use. In conclusion, this study suggests that the need for uniqueness is not only directly associated with problematic Internet use in adolescents but also through stress and the chain mediating effect of stress and ego depletion. These findings support the Person-Affect-Cognition-Execution model for Internet addiction (I-PACE) and provide new insights for the prevention and intervention of problematic Internet use.