The invention relates to a predicting method for an aircraft track based on 4D. An air traffic control system comprises a data communication module, a monitoring data fusing module, an onboard terminal module and a control terminal module, wherein the monitoring data fusing module is used for realizing the fusion of air traffic control radar monitoring data and automatic related monitoring data and supplying real-time track information to the control terminal module; and the control terminal module comprises two sub-modules for generating a conflict-free 4D track before flight and generating a 4D track in medium/short period of flight. According to the systemic predicting method for the aircraft track, the control terminal module is adopted for processing flight planning data, and a hidden Markov model is utilized to generate the 4D track, so as to realize the analysis for the potential traffic conflict under the air traffic condition. According to the method provided by the invention, the safety of the air traffic can be effectively increased.