Abstract: To study the interference characteristics of cluster munition separation by multi-bay assemblage, the model was designed by selecting the cluster munition system with two bays. Based on the finite volume method and combining ALE(Arbitrary Lagrange-Euler) equations, together with dynamic mesh method, the characteristics of three-dimensional flow fields such as the flow interference characteristics in the different separation conditions were analyzed. The processes of submunition separating form dispenser were simulated by coupling fluid equations and 6DOF(six degree-of-freedom) moving equations. The variation of flow characteristics and the aerodynamic coefficients curves along flight history of the bullet in the different separation bays were presented as the result. The interaction process of separation and the difference of flow interference characteristics between the bullets were analyzed . The results offer reference for further study on the characteristics of the cluster munition separation flow field.