Abstract: This study analyzes the distribution level of China’s airport cargo scale system (Zipf index) based on the Rank-Size Rule. The results show that: at present, China’s airport cargo scale system presents a “4+3+N” spatial development pattern with Shanghai Pudong, Beijing Capital, Guangzhou Baiyun and Shenzhen Baoan airports as the core hubs, and Chengdu Shuangliu, Hangzhou Xiaoshan and Zhengzhou Xinzheng airports as the regional hubs; the Zipf index of China’s airport cargo scale system is lower than that of the United States, which is 15.11% in the same period, and has gradually declined in recent years; the estimation results of the spatial lag model (SLM) considering spatial dimensions show that there is spatial competition in China’s airport cargo scale system and its Zipf index was between 0.505 and 0.597 from 2009 to 2018, while the OLS model overestimated the Zipf index of China’s airport cargo scale system by 12.04%. This paper studies the distribution level of China’s airport cargo scale system with quantitative methods and aims to provide a new basis for industry managers and policy makers to optimize China’s airport cargo scale system.