As an emerging financial model created by technological empowerment, digital finance has significantly impacted green innovation. However, research on the spatial spillover impact of digital finance on green innovation efficiency (GIE) is rather lacking. To fill this gap, this paper constructs a Spatial Durbin Model (SDM) to analyze the spatial spillover effects and regional heterogeneity of digital finance on enhancing GIE, based on the measurement of the GIE in 271 prefecture-level cities in China during 2011-2021 by applying the SBM model. Furthermore, the impact path is explored at the end. The results reveal that: (1) The GIE in China remains relatively low, and the average value of GIE in China and its four regions exhibits a fluctuating upward trend and presents as follows: East>Northeast>Central>West; (2) The spatial spillover effect of digital finance on GIE shows that it significantly promotes GIE locally and suppresses the GIE in the adjacent cities; (3) Heterogeneity analysis shows that in central cities, low-carbon pilot cities, and cities with higher human capital, the impact of digital finance on GIE is more significant; (4) The spatial effect of digital finance on GIE is moderated by human capital.