Background <p>Although the relationship between social media use and insomnia has been confirmed, few studies have explored the association between social media overload and insomnia, and the underlying mechanism is still unclear. The present research aims to propose a theoretical model in which information strain and depressive symptoms serve as mediating variables between social media overload and insomnia, providing new empirical evidence for the impact mechanism of insomnia.</p> Methods <p>644 college students participated in the questionnaire survey, they all completed a self-report questionnaire with demographic information, social media overload, information strain, depressive symptoms, and insomnia. The data were processed using SPSS26 and the PROCESS4.0 tool.</p> Results <p>Social media overload, information strain, depressive symptoms, and insomnia were positively and significantly associated with each other. Information strain and depressive symptoms mediated the association between social media overload and insomnia. There also existed a chain-mediating effect between social media overload and insomnia.</p> Conclusions <p>This study highlights the potential negative effects of social media overload on sleep problems. The results of this article emphasize the importance of promoting good social media usage habits and healthy lifestyles during public health emergencies, which are important for improving health outcomes.</p>