In order to alleviate the collision risk of non-intersecting runways simultaneous operation, it is necessary to apply a control strategy conforming to the operation characteristics. A collision risk assessment model was constructed by using event tree analysis and Monte Carlo method. Based on event tree analysis, the event to be solved was determined. The probability of related events was calculated by Monte Carlo method. By statistical and fitting the collision event data obtained by the experiment, the safety target level was standardized and the control strategy was put forward. Finally, taking the approach of 01L and the departure of 29R on the non-intersection runways of Daxing Airport as an example, the departure shielding window (0.41 ~ 7.39 km) was obtained. Using this strategy, the risk of aircraft collision can be controlled at an acceptable level. The proposed computational model of departure shielding window is of general applicability to the formulation of safe operation control strategies for non-intersecting converging runways.