Aiming at the development requirements for internal bay multi-stores separation in next-generation advanced fighter aircraft, this study systematically investigates the flow field characteristics and motion patterns during multiple store separations using overset grid technology and the NNW-FlowStar solver. By establishing three typical configuration models (lateral, axial, and longitudinal configurations), the release processes of two/three-store and multi-store configurations are analyzed in depth. Key findings include: 1) Store separation motion is dominated by pitch motion, with its attitude evolution significantly influenced by Mach number. At Ma = 0.8, the collision occurrence time for lateral two-store configurations advances by 0.06 s compared to Ma = 0.6, accompanied by an 83% increase in pitch angle amplitude. 2) Lateral configuration exhibits distinct flow field symmetry, the axial configuration demonstrates pronounced flow field periodicity, while configurations with smaller inter-store spacing (lateral and longitudinal) demonstrate higher collision probabilities than axial configurations, respectively. 3)Multi-body coupling effects intensify with increasing arrangement density. Critical collision times advance by 0.2 s (34%) for lateral configurations and 0.12 s (20%) for longitudinal configurations when transitioning from dual-store to triple-store configurations. The research elucidates aerodynamic interference mechanisms during multi-body separation and establishes qualitative/quantitative relationships between inter-store spacing, Mach number, configuration types, and separation dynamics. These findings provide critical guidance for the separation design of internal bay multi-stores.