The carbon emissions trading is not only an inevitable choice to achieve the "dual carbon" goal, but also an important way to promote China''s regional economic green growth. Based on the theory of porter hypothesis and new development concept, the impact mechanism of carbon trading pilot policies on China''s regional economic green growth was explored. The pilot policies were treated as a quasi-natural experiment. Based on the panel data of 30 provinces in China from 2005 to 2018 (Hong Kong, Macao, Taiwan and Tibet are not included due to incomplete data), the double-difference model was used to empirically examine. The results show that: (i)The carbon trading pilot policy has significantly promoted China''s regional economic green growth. There is a positive cumulative dynamic effect. After placebo test and PSM-DID test, the conclusion is still robust. (ii)Further research shows that there is regional heterogeneity in the impact of carbon trading pilot policies on China''s regional economic green growth. The promotion effect of policies in the eastern region is significant, while that in the central region is not obvious, and the western region shows an insignificant inhibitory effect. (iii)Mechanism research shows that carbon trading pilot policies achieve China''s regional economic green growth through promoting green technology innovation, adjusting industrial structure, optimizing energy structure, absorbing foreign direct investment and promoting shared development. Among them, the intermediary effect of shared development is the largest, followed by green technology innovation and industrial structure. While the intermediary effect of energy structure and foreign direct investment are small. (iv) Sub-regional mechanism test found that the intermediary effect of shared development in the eastern region is the largest, followed by green technology innovation and industrial structure, the intermediary effect of energy structure is the smallest. The largest intermediary effect in the central region is energy structure, followed by green technology innovation, and the transmission effect of foreign direct investment is relatively small. The intermediary effect of industrial structure in the western region is the largest, while the intermediary effect of energy structure and foreign direct investment is relatively small.