The green tax system is an important tool for the government to coordinate the contradiction between economic development and environmental governance using fiscal instruments, and green tax reform can play a regulatory role in carbon emissions. This study analyzes the impact of the green tax system on carbon emissions of industrial enterprises by using the difference-in-differences model based on panel data for A-share listed industrial enterprises from 2014-2021 in China. The results show that: (1) Environmental Protection Tax Law significantly reduces corporate carbon emissions; (2) Among state-owned and heavy polluting industrial enterprises, enterprises with low financing constraints and a high degree of regional marketization, this negative effect is more pronounced; (3) Environmental Protection Tax Law motivates enterprises to implement carbon emission reduction activities through two paths: increased environmental protection investment and improved green innovation, thus promoting the transition to low-carbon development.