Abstract: China's civil aviation enterprises consume large amounts of energy in the process of development and operation and thus shoulder an important responsibility for carbon emission reduction. This study takes the performance of China's major civil aviation enterprises from 2015 to 2023 as the research object, and selects 10 indicators such as fleet size, number of flights, passenger volume and cargo volume as the observation variable indicators. The observation variables are used as the reflection indicators of operation level, transportation capacity, enterprise scale and carbon emissions. The partial least squares structural equation model (PLS-SEM) is used to analyze the action path and effect of various influencing factors of carbon emission of civil aviation enterprises. The results show that the level of operation directly affects carbon emissions, and the direct effect is 0.753. The operation level plays a completely positive mediating role in the impact of enterprise size and transportation capacity on carbon emissions, and the mediating effects are 0.349 and 0.382, respectively. According to the research results, the analysis and interpretation are made, and relevant suggestions are put forward for China's civil aviation enterprises.