In order to improve the safety operation ability of aviation network, a key node identification method based on kernel extreme learning machine is proposed. Firstly, it evaluates the comprehensive importance of nodes based on analytic hierarchy process (AHP). Then, it selects three simple indices and establishes the importance evaluation model based on the mapping relationship between simple indices and comprehensive importance of kernel extreme learning machine. Simulation results show that the proposed method is accurate in evaluation and can overcome the problem of high computation time complexity.