BACKGROUND: Social attachment has been identified as a key antecedent motivating users’ social media involvement. However, there is a scarcity of research investigating whether and how three dimensions of social attachment exert impacts on users’ continuous usage intention of social media. OBJECTIVE: Based on structural equation model analysis, the current research clarifies the relationships between social attachment, affective commitment and social media continuous usage intention, which unveils the underlying mechanism through which three dimensions of social attachment influence users’ continuous usage intention of social media. METHODS: A survey was conducted with 536 informative responses obtained from TikTok public users for hypothesis testing analysis. RESULTS: Results indicate that three dimensions of social attachment (social connections, social dependence and social identity) are all positively related to users’ continuous usage intention of social media. Affective commitment partially mediates the relationship between social attachment and users’ continuous usage intention of social media. CONCLUSIONS: The current research makes an in-depth study about the underlying mechanism whereby social attachment exerts impacts on social media continuous usage intentionand provides several managerial and theoretical implications. Future research directions are discussed as well.