Against the backdrop of globalization-driven succession challenges in family businesses, this study investigates how overseas-versus domestically-educated second-generation successors shape corporate social responsibility (CSR) performance, leveraging big data analytics on China’s A-share listed family firms from 2010 to 2020. Results reveal that while successors overall show no CSR performance gap compared to founders, those with overseas backgrounds exhibit significantly weaker CSR commitment than domestically trained successors. Heterogeneity analysis shows that the time of the second-generation successors’ internal experience before succession, the time of holding power after succession, the disciplinary background, and the government-enterprise relationship in the region will all have a different effect on the background difference of the second-generation successors and the relationship between CSR commitment. Mechanism analysis shows that the political connection of second-generation heirs can mitigate the negative impact of their overseas background on CSR to a certain extent. This study not only enriched the theory of intergenerational inheritance of family businesses, but also provided practical guidance for how to train second-generation heirs with social responsibility in family businesses.