Abstract: This study selects A-share listed heavy industrial enterprises as samples between 2010 and 2022, and empirically analyzes the effect of China's carbon emissions trading pilot policy on enterprises' green technological innovation using the difference-in-difference method. The results of the study show that the carbon emissions trading pilot policy significantly promotes the green technology innovation of heavy industry enterprises. The robustness test shows that the policy has the most significant effect on the promotion of green technological innovation of heavy industry enterprises in the early stage of implementation and the lag 1-2 period. Heterogeneity analysis shows that there are significant differences in the response of different types and different heavy industry enterprises to the carbon trading policy in terms of green technological innovation, among which state-owned enterprises and large-scale enterprises are more sensitive to the policy, and raw material industry is more sensitive to the policy than processing industry. more sensitive to the policy, and the raw material industry is more sensitive to the policy than the processing industry.