Abstract: International aviation carbon emission reduction is a crucial component of global climate governance system. The cross-border nature of international air transportation rendered it difficult to achieve emission reduction targets solely through national efforts, so the “Kyoto Protocol” authorized the International Civil Aviation Organization (ICAO) to establish a carbon emission reduction mechanism in the field of international air transportation. Over the years, the global climate governance system has undergone great changes. The “Kyoto Protocol” has essentially lost its legal force, and the “top-down” emission reduction model established by it has been replaced by the nationally determined contribution model of the “Paris Agreement”. Despite this, the ICAO still promotes the “top-down” emission reduction model in terms of international aviation carbon emission reduction. This model is guided by collective goals and bound by resolutions and international standards, promoting international aviation carbon emission reduction through technical goals and standards. At the same time, it establishes a market-based CORSIA mechanism to help aircraft operators offset carbon emissions when technology fails to achieve emission reduction goals. China’s aviation industry will continue to grow rapidly on the basis of its current scale and will face tremendous pressure for carbon emission reduction. Therefore, it is necessary to seriously implement the national carbon peak and carbon neutrality goals, actively participate in global climate governance, and coordinate the rule of law in domestic and foreign-related affairs. In addition, it is essential to deal with possible international disputes, strengthen technology and standard guidance, and realize the transformation of green development of the whole industry while promoting international aviation carbon emission reduction.