Abstract: In order to intelligently handle the complex situation contained in air traffic data, an ATC complex event processing system is designed and implemented based on complex event processing technology for data processing and Web visualization based on the characteristics of the ATC field. Three types of ATC complex event patterns were developed with reference to civil aviation industry regulations and professional knowledge: aircraft safe separation warning, aircraft altitude change abnormality, and aircraft encountering bad weather. The application scenarios were simulated under real data to detect the above patterns. The results show that the system can detect ATC complex events with millisecond processing delay and provide intelligent technical support for ATC work.