Drawing from the 2015-2021 panel data of China's A-share listed companies, this study employs multiple regression analysis to assess the impact of corporate digital transformation (CDT) on ESG performance. Findings suggest a significant positive correlation between the degree of CDT and ESG outcomes. As CDT intensifies, there's a marked improvement in ESG performance. Further analysis uncovers a threshold effect in this relationship, implying the most pronounced positive influence on ESG emerges after reaching a certain level of digital transformation. Robustness checks confirm these core findings. Moreover, the level of corporate profitability doesn't mitigate the positive correlation between CDT and ESG performance. This positive relationship remains significantly evident across both state-owned and private enterprises, with a heightened correlation observed in the state-owned segment. This research enriches the theoretical understanding of the nexus between digital transformation and corporate social responsibility, buttressed by empirical evidence.