With the increasing number of flight flights and the increasingly crowded air traffic conditions, the air traffic management industry is facing enormous security pressure. In this paper, the method of air traffic control unsafe event warning is studied, the basic principle of air traffic control unsafe event warning system is analyzed, and the guiding idea and function of air traffic control unsafe event warning system are described. Finally, from the four aspects of people, equipment, environment and management, the early warning index system of air traffic control unsafe events is constructed, and the meanings and measurement methods of each index are put forward.