The scientific and systematic nature of local government carbon emission policy systems plays a crucial role in achieving the carbon peak and carbon neutrality goals. This study constructs a policy evaluation system based on the PMC index model to quantitatively assess carbon emission policies in Hunan Province before and after the introduction of the “dual carbon” goals. The findings indicate that the average PMC index for Hunan Province’s carbon emission policies is 6.81, reflecting an overall good level. After the introduction of the “dual carbon” goals, policy quality improved significantly, with the average PMC index rising from 6.12 to 7.50. The policies perform well in terms of timeliness, functionality, and transparency, but there is room for improvement in incentive mechanisms, implementation levels, and public participation.