In order to study the dynamic impact effect of armed helicopter air-to-ground missile during launching, the block hybrid grid model combined with three-dimensional unsteady Navier-Stokes equations and dynamic grid method was used to calculate the jet impingement flow field of armed helicopter air-to-ground missile during launching. The effects of flow field impingement on the aircraft with external guideway structure are compared under the launch condition near the fuselage skin and the launch condition near the wing tip. The results show that the initial shock wave flow field development process is similar in the two conditions, and the overpressure distribution is a single-peak function, but the positive and negative pressure peaks of the overpressure at the fuselage are significantly larger in the near-fuselage skin launching condition; The change rate of the maximum impact load on the launcher in all directions caused by the missile launched near the wing tip is larger than that of the missile launched near the fuselage skin.The overpressure load and the impact force on the wall caused by the initial gas shock wave are closely related to the launch scheme, the area of the helicopter near the missile, the distance between the missile and the fuselage skin, and the distance between the missile and the wing tip.