Based on the matching sample of China Customs data, CEPII-BACI data, and listed company data from 2009 to 2016, combined with the Hua Zheng ESG rating system, this paper examines the impact of corporate ESG performance on export technology complexity and its underlying mechanisms. The findings reveal a U-shaped relationship between corporate ESG performance and export technology complexity. Specifically, ESG governance initially reduces export technology complexity but ultimately promotes its improvement in the long run. Heterogeneity analysis indicates that the positive effect of ESG performance is more pronounced for state-owned enterprises and general trade enterprises. Mechanism tests demonstrate that corporate ESG performance influences export technology complexity primarily through three channels: the“cost effect”“R&D innovation effect”and“financing constraint effect.”This study not only deepens our understanding of how ESG performance shapes corporate export outcomes from a novel perspective but also provides actionable insights for firms to enhance export competitiveness and adapt to evolving global trade dynamics through ESG governance.