Abstract: The complicated unsteady aerodynamic interference of airplane and aviation bomb is come into being during the separation process. Especially in the initial separation process, the aerodynamic interference will be changed the aviation bomb’s aerodynamic and flight characteristic significantly. And the security of the separation process of airplane and aviation bomb may crash with the airplane on account of the aerodynamic interference of them. So it is essential to analyse the interference flow fluid of airplane and aviation bomb, it may crash with the airplane on account of the aerodynamic interference of them and is also necessary for us to investigate into the interference aerodynamic characteristics of three-dimensional internal aviation bomb during the separation process.Dynamic mesh technique and three-dimensional unsteady numerical simulation method are used to simulate the process of separation between three-dimensional internal aviation bomb and openbay dispenser. The interference flow fluid of three-dimensional open-bay dispenser and internal aviation bomb during separation are obtained. And the interference aerodynamic characteristics of three-dimensional internal aviation bomb during the separation process are gained. Three-dimensional internal aviation bomb separation trajectory is given in the end.