Aiming at the problem of separation assurance between two aircraft under the sequential flying conditions when the leading aircraft decelerating, the hybrid separation assurance strategy combined heading adjustment and true airspeed adjustment based on receding horizon control was proposed considering the random disturbance factors on the route. Three separation assurance strategies， including static offline optimization without counting the random disturbance, dynamic optimization of speed adjustment and hybrid separation assurance control law, were compared. In the simulation, an aircraft that adopted static offline strategy without considering the random disturbance did not return to the route centerline after the end of the predicted maneuver time; an aircraft that adopted speed adjustment separation assurance strategy completed the maneuver in 254 s; and an aircraft that adopted hybrid separation assurance strategy with speed adjustme-nt and heading adjustment completed maneuver in 97 s, a maneuvering efficiency increased by 61.8%. The re-sults show the effectiveness, efficiency and robustness of the hybrid separation assurance strategy.