Abstract: During the separation of high-speed multi-bodies, shock interference causes sharp changes in aerodynamic loads and flight attitude instability. Based on numerical simulation, this paper uses a simplified sharp wedge model to study the evolution of shock interference and their influence on son wedge force under different son wedge degrees of freedom and initial separation velocities. The results show that degrees of freedom significantly affects the separation process: when the son wedge moves at constant speed (constrained degrees of freedom), the flow field has a self-similar wave system stage and aerodynamic force finally reaches a plateau; when the son wedge moves freely, the angle of attack increases continuously (exceeding 90° under some conditions), leading to shock detachment and serious impact on separation safety. Meanwhile, initial separation velocity is also a key factor for separation safety: A higher initial separation speed is conducive to separation safety. When the initial separation speed is lower, the son wedge is subjected to greater negative lift, and the wave system becomes more complex. The study also finds that aerodynamic characteristics of the son wedge under all conditions are related to the wave configuration, and the transition of wave configuration corresponds to the inflection point of the son wedge force coefficient, indicating that shock wave interference is the core mechanism dominating aerodynamic characteristics. This study provides a theoretical basis for the safe and controllable separation design of high speed multi-bodies.