To conduct an in-depth study of the fractal characteristics of China’s airway network, unweighted and weighted national and regional airway networks were constructed through length-radius dimension calculations and length measurement methods. Empirical analyses were then performed from several perspectives, including urban nodes, national airway networks, geographical regions, and regional airway networks within airport clusters. The results show that the fractal dimensions of the unweighted and weighted national air route networks are 1.540 0 and 1.488 1, respectively. For the unweighted air route networks in Northern China, Southern China, Northwest China, and Qinghai-Xizang region, the fractal dimensions are 1.573 4, 1.679 4, 0.971 1, and 0.980 0, while those of the regional weighted air route networks are 1.244 0, 1.621 3, 0.883 0, and 0.982 9. The fractal dimensions of the unweighted air route networks of the four airport clusters are 1.118 1, 1.154 4, 1.020 7, and 1.218 0, and the corresponding values for the weighted networks are 0.930 3, 0.893 5, 0.957 6, and 1.166 3. The results indicate that China’s air route network exhibits obvious fractal characteristics and is a typical multi-hub network. In addition, the density distribution of air route networks in various regions is uneven, and the displayed fractal characteristics are also different. The air route networks in Northern China and Southern China both belong to multi-hub networks with high route density, while the Qinghai-Xizang Region and Northwest China show a unipolar network structure, where flight operations rely more on the transfer function of hub airports. The air routes of the three airport clusters (Beijing-Tianjin-Hebei, Yangtze River Delta, and Pearl River Delta) are highly concentrated in their respective hub centers, presenting a unipolar hub pattern. In contrast, the Chengdu-Chongqing Airport Cluster has not formed a weighted air route network structure dominated by an absolute hub.