Evaluating the impact of carbon emissions trading (CET) policy on the operations and development of high-carbon enterprises is of great practical importance in a context where policy-makers aim to balance steady growth and reduce carbon emissions. Based on the panel data of A-share listed enterprises, this paper comprehensively employs the difference-in-differences (DID) and the difference-in-differences based propensity score matching (PSM-DID) methods to investigate the impact of China’s CET policy on the financing constraints and financing ability of high-carbon enterprises. The results indicate that: first, the level of financing constraints of high-carbon enterprises in China has significantly increased with the implementation of the CET policy from 2012 to 2019. Second, the impact shows significant heterogeneity in various industries, carbon markets, and the characteristics of enterprises. Third, the CET policy reduces the long-term debt financing ability of high-carbon enterprises by 22.26 percent during the sample period, but it has no significant impact on short-term debt financing ability. JEL Classification: C33, D92, G32, Q43, Q58