Abstract: The rapid growth of carbon dioxide emissions from China’s civil aviation has become a major obstacle to achieving the “dual carbon” goals. To accurately assess the decoupling status in the process of China’s civil aviation development and understand the key influencing factors and mechanisms of decoupling at different stages of development, this study comprehensively accounts for China’s civil aviation carbon emissions, using the panel data from 2000 to 2019 and the IPCC method. Based on this account, an LMDI-Tapio model is constructed. The results show that China’s civil aviation carbon emissions generally follow a trend of continuous growth in total volume but a decline in intensity year by year. However, future improvements in energy efficiency are limited. The level of national economic development is the primary driving force behind carbon emissions, while energy consumption intensity is the driving factor for long-term emission reduction. The decoupling relationship between aviation carbon emissions and turnover, as well as industry income, has gradually shifted from weak decoupling to expansionary connection and expansionary negative decoupling. This indicates a further compression of emission reduction space for the industry, resulting in dual pressures on industry development and environmental protection. The economic development level, transport intensity, and population size do not have a positive impact on decoupling, while energy consumption intensity promotes decoupling of carbon emissions and turnover. Additionally, industrial structure has made the greatest contribution to promoting decoupling for industry development. This research provides a theoretical basis and empirical evidence for the formulation of carbon reduction policies in the civil aviation sector.