Digital trade, as one of the vanguards of the global technological revolution and industrial transformation, empowers low-carbon economic cooperation on a global scale. This study based on panel data from 2007 to 2021 of 46 countries with varied development levels, constructed a multi-dimensional indicator system from six aspects: trade potential, digital infrastructure, digital innovation, digital skills and security, scale of digital trade, and digital trade environment, aim to measure the development level of digital trade and explore its impact on carbon emissions, followed by a heterogeneity analysis. The research results indicate that there are significant differences in the development levels of digital trade among countries with different economic strengths. Countries with stronger economic power and larger trade scales have a higher level of digital trade development, while less developed regions lag in digital trade. As the level of digital trade development increases, the impact of digital trade on carbon emissions will also change. Overall, digital trade exhibits a pronounced low-carbon effect, while its impact varies among countries with different development levels.