Previous evidence suggests that the amount of support one received has an impact on the cognitive empathy, however, it is not clear what mechanism underlies this relationship. The present study examined the mediating and moderating mechanism between family support and cognitive empathy in 2,023 college students who completed self-report questionnaires assessing their level of family support, core self-evaluation, cognitive empathy and problematic mobile phone use. The results indicated that family support was positively associated with cognitive empathy. A mediation analysis indicated that core self-evaluation mediated the relationship between family support and cognitive empathy. Furthermore, the effect of core self-evaluation on cognitive empathy was moderated by problematic mobile phone use, depending on the level of core self-evaluation. When the core self-evaluation level of college students is high, the higher the degree of problematic mobile phone use, the lower the level of cognitive empathy ability; when the core self-evaluation level of college students is low, the situation will be the opposite. The current research reveals that family support can enhance core self-evaluation, thereby affecting cognitive empathy, and the effect of core self-evaluation on cognitive empathy was moderated by problematic mobile phone use.