Abstract: Based on the panel data of 25 prefecture-level cities in Huaihe River Economic Belt from 2008 to 2018, this study uses SBM-ML model to measure the green TFP of Huaihe River Economic Belt, and empirically analyzes the effect of fiscal decentralization and environmental regulation on green TFP. The results show that the green TFP of Huaihe River Economic Belt is growing, and the growth rate of sea-river-lake linkage zone in the East is the highest; fiscal decentralization has a negative effect on green TFP and green technology progress, and environmental regulation can significantly promote the growth of green total factor productivity, green technology efficiency and green technology progress; fiscal decentralization has a threshold effect on green total factor productivity and green technological progress. When the intensity of environmental regulation is too high, fiscal decentralization can further deepen the negative effect on green total factor productivity by reducing the level of economic growth.