To assess and improve the operation system of paired takeoff separation and reduce the risk of wake turbulence encounters during paired takeoff, a computational fluid dynamics (CFD) method is used to study the operational conditions and wake turbulence safety intervals of paired takeoff separation mode. Firstly, the safe area of wake turbulence under the paired takeoff separation mode is analyzed, and a safety interval model is constructed. Secondly, the SST k-ω turbulence model is selected, and a numerical simulation method for the wake flow of the leading aircraft before the pairing is established based on CFD. Finally, a calculation method for the safety interval of paired takeoff separation is established.Taking Hongqiao Airport as an example, A320-200 and B737-800 are selected as the leading and trailing aircraft, and the wake flow field is simulated at 0, −1, and −2 m/s crosswind conditions. The simulation results are then used to analyze the operational conditions and safety intervals of paired takeoff separation mode. The results provide data support for the implementation of the paired takeoff separation mode and demonstrate the applicability of the CFD method in studying aircraft wake turbulence.