The digitalization of finance drives economic development and plays a crucial role in energy conservation and carbon emission reduction. Utilizing carbon emissions data from 2011 to 2020, we find that digital finance development can mitigate carbon emissions intensity (CEI) by approximately 0.14 %. Then, we employ a diverse set of robustness and endogeneity tests to assess the reliability of the empirical findings. Moreover, the study delves into how digital finance impacts CEI through production technology innovation (PTI) and green technology innovation (GTI). The results indicate a positive effect of PTI on CEI. GTI exerts a negative influence on CEI. In addition, there is a chain mediation effect between PTI and GTI in the baseline path. Finally, the impact of digital finance on CEI exhibits apparent regional heterogeneity.