In order to analyze the multi-body flow characteristics and the aerodynamic interference characteristics for the sub-munitions in different bays under sequential separation, the three-dimensional unsteady flow field of the cluster munition under two types of sequential separation and single separation style was simulated with the use of the unstructured dynamic mesh method, based on the governing equations of fluid dynamics and rigid body motion equations of 6DOF (degree of freedom). The variation of the flow characteristics and the aerodynamic interference characteristics of sub-munitions in different separation styles was shown and the interaction process of aerodynamic interference between the sub-munitions in different separation stages was revealed as the results. Numerical simulation results show that the flow characteristics become more complicated and the aerodynamic separation parameters of the rear sub-munition become lower than that of the front sub-munition because of the shock wave interaction between the sub-munitions in the process of sequential separation. During the short sequential separation, the interference from the front sub-munition to the rear sub-munition is more severe so that the security of the separation between the sub-munitions is affected.