In order to unveil the overall states and dynamic variation of conflict risks for converging air traffic,a conflict risk assessment method based on Monte Carlo simulation was proposed.Based on the analysis of the geometry characteristic of the converging airways,the conflict route segment model is proposed to determine the conflict ranges that are caused by converging air traffic.The conflict risk assessment method based on the Monte Carlo Simulation was designed.The conflict risks of converging air traffic were assessed from macroscopic and microscopic levels by comparing the 4D trajectories,conflict rate,conflict severity,conflict risk and total conflict risks.Finally,the conflict risks were as-sessed for the convergence of Route A593 and Route R343 at VMB by the simulation as an example based on statistical a-nalysis of historical operation data.