Based on theoretical analysis, this paper constructs a comprehensive index system to measure the development of digital economy from four dimensions: digital infrastructure, digital economy penetration, network information resources, and digital economy environment and effects, and uses the time serial generalization principal component analysis method to measure the provincial digital economy development level index of China from 2006 to 2019, and establishes two stage least squares method and panel threshold model to analyze the relationship between digital economy and green total factor productivity. The study finds that the digital economy significantly promoted to the improvement of Chinas green TFP, become a new driving force to support Chinas green TFP improvement in the new development stage, and this research conclusion is still robust after a series of robustness tests. The mechanism of action finds that the digital economy can promote to green TFP growth by stimulating enterprises to increase R&D investment and promoting the optimization and upgrading of industrial structure. The green productivity growth effect of the digital economy is further enhanced by the higher level of digital economy development and the higher intensity of regional IPR. Compared with the eastern region, the increase in the level of digital economy development in the central and western regions has a more obvious positive impact on green TFP. Our research not only provides an empirical basis for assessing the impact of the digital economy, but also theoretical references for promoting the development of domestic green transformation through the digital economy.