<p>China’s Belt and Road Initiative (BRI) holds significant potential to reshape the global path toward sustainable development. Yet, its implementation outcomes across participating countries remain underexplored. This study employs a super-efficiency Epsilon-Based Measure (EBM) model with window analysis to assess green total-factor productivity (GTFP) in 42 BRI countries from 2000 to 2020. Then, an energy trilemma index (ET) is constructed using the entropy weight method based on three dimensions: energy security, energy equity, and energy greening. Finally, the difference-in-differences (DID) approach is applied to examine the policy effects of the BRI on GTFP and ET. The findings reveal three key insights. First, Only 13 countries experienced growth in GTFP. The regional heterogeneity analysis show that East Asia and the Pacific achieved the highest levels of GTFP, whereas the Middle East and Africa showed the lowest performance. While the energy trilemma exerts a positive linear effect on green productivity, its impact becomes even stronger when the interaction term between the energy trilemma and the BRI (ET×BRI) is incorporated. The results indicate that geopolitical risk (GPR) undermines GTFP directly. However, its interaction with the BRI (GPR×BRI) exerts a positive moderating effect. This implies that the BRI has the capacity to promote green productivity in an evolving geopolitical context through enhanced cooperation. These findings inform policy decisions and support BRI countries in advancing both green growth and energy transition.</p>