Finance is the foundation and important pillar of national governance, and tax revenue is one of the core elements of finance. This paper analyzes the development history of China's green tax system since the founding of the People's Republic of China and evaluates the greening degree of China's tax system from the revenue benefit and environmental benefit of green tax. The study finds that the greening degree of China's tax system has been deepening, from the tender green budding period to the light green development period and then to the deep green development period. With the proportion of green tax revenue gradually increasing, the energy continuing to improve, energy efficiency continuing to improve, the effect of reducing pollution and carbon is remarkable. Under the guidance of achieving carbon peak carbon neutrality, China's green tax system still has room for continuous deepening of reform, and there is still a long way to go to deepen the greening degree of tax system through taxation reform.