Abstract: The issue of shock reflection during multibody separation is one of the key factors affecting the flow field structure and the safety of vehicle separation. In this study, a simplified wedge model is employed and numerical simulations are conducted to investigate the effects of four critical parameters: nose radius, inclination angle, relative spacings between the wedge and the reflection surface, and wedge velocities. A simplified wedge model and a flat plate are employed. The results indicate that increasing the inclination angle or reducing the relative spacing delays the critical time of shock reflection type transition. However, excessive inclination angles or overly small relative spacings may cause shock detachment due to large flow deflection angles or instability of the Mach stem, ultimately leading to no reflection phenomena. Higher wedge velocity advances the critical time, with its influence on the shock system mainly concentrated in the transition stage of shock reflection types. In addition, variations in nose radius are also confirmed to have a significant impact on shock evolution. Shock reflection types exert a pronounced influence on the evolution of aerodynamic coefficients, particularly during the transition from no reflection to Mach reflection. This study reveals the governing effects of multiple parameters on shock reflection and provides theoretical guidance for the design of separation schemes in high speed multibody vehicles.