China's air traffic flow management business is in the charge of the Operation Management Center of the Air Traffic Management Bureau affiliated by the Civil Aviation Administration of China. When the national air traffic flow exceeds the capacity (the critical value), and the workload of controllers is expected to be too large, the Operation Management Center will control and limit the air traffic to prevent the flow from exceeding the capacity. While the Operation Management Center also presents many inconveniences in the process of managing and controlling the national traffic.Therefore，the behavior of air traffic controllers in dealing with actual traffic is measured and analyzed, the actual air traffic flow is recorded as well,the air traffic smoothness is also calculated, flinally, the relationship between the traffic fluency and the workload of air traffic controllers is determined. It follows that, it can be concluded that in air traffic flow management, air traffic smoothness could be used to provide decision-making support for air traffic flow management units.