The development of green finance helps to promote the transition to a low-carbon economy. Using data from 30 provinces in China from 2001-2019, we empirically examine the impact of green finance on the transition to a low-carbon economy and further explore the mediating role of low-carbon technological innovation in this facilitation process. The study finds that (1) green finance can significantly contribute to the transformation of the low-carbon economy from China as a whole. However, when China is divided into four regions: east, central, west and northeast, the contribution of green finance to the low-carbon economic transition in the west is not significant. (2) After adding low-carbon technologies to the model, green finance still has a significant contribution to the low-carbon economic transition, but this contribution decreases with the intervention of low-carbon technologies. (3) There is a strong spatial dependence between green finance development and low-carbon economic transformation in 30 Chinese provinces. However, the dependence among provinces tends to weaken after 2011. And the overall green financial development in China shows a positive spillover effect on the low-carbon economic transition. Based on the analysis results, several countermeasures are proposed to promote the further development of China's low-carbon economy.