Abstract: Aft ejection of missile has the potential of becoming a feasible choice for carrier releases while traveling at a supersonic/hypersonic speed for its obvious advantages in heat protection, shape-preservation, stealth, repeated-release and recycling. Thus, it causes a new type of multi-body separation problem: aft supersonic/hypersonic ejection separation(ASES). The essence of ASES problem is the supersonic/hypersonic cavity-base flow coupled with multi-body separation, which has complex flow structures and notable unsteady nonlinear asymmetric aerodynamic effects. In order to explore the structure of interference flow field, the ASES was studied with grid and captive trajectory system(CTS) wind tunnel test methods. Four typical types of interference based on flow structure and variation of control effectiveness were obtained. They are low speed and subsonic flow field without shock, high subsonic and transonic flow field with weak shock, supersonic flow field with shock, and quasi-freestream with diminishing impact. The rule of aerodynamics and characteristics of control effectiveness within wake interference were revealed, as well as the influence of control law, angle of attack, altitude and Mach number on non-dimensional displacements and attitudes of separation. The insight into ASES will be enhanced and engineering practice will be boosted by the conclusions.