With the continuous increase of air traffic volume, the vulnerability of the air route network topology has become increasingly prominent, and its robustness optimization has become increasingly important. This paper proposes a method called prefrential configuration node-protecting cycle(PCNC) that uses complex network theory to analyze the topology structure of air route network. Based on degree fitness technology, it detects key nodes with large degree values of itself and neighbor nodes, increases links, configures node protection rings, and optimizes air route network topology robustness. Taking the air route network in the mainland of China as an example, 1 017 waypoints and 1 568 segments were selected; 101 key nodes were detected; and 56 new edges were configured. Combined with random attacks and attempted attacks based on node degrees, robustness of the air route network topology for both attack modes is significantly enhanced after optimized, and the robustness of the ARN topology under deliberate attacks is better.