Abstract: In order to accurately simulate the multi-body separation process of hypersonic vehicle with equivalent mass and volume, a dual-body synchronous captive trajectory test technique in the hypersonic wind tunnel is developed for the first time. Based on this technique, the dual-body synchronous separation test platform of the hypersonic wind tunnels is established in the four-in-one design mode, which combines four key functionalities together, i.e., data acquisition of the total pressure and total temperature of the wind tunnel settling chamber, the forces from the balance mounted on the models, etc., real-time aerodynamic and dynamic calculations, linkage combination control of the upper/lower mechanism, and motion distribution of the upper/lower mechanism. Taking advantages of the standard model of TSTO (Two-Stage-to-Orbit), the test verification of typical states of the dual-body CTS (Captive Trajectory System) at Mach 6 is carried out in the Φ1m hypersonic wind tunnel. The verification results show that the established dual-body synchronous separation test technique in the hypersonic wind tunnel can well obtain the two-stage separation trajectory and the aerodynamic characteristics of the hypersonic aircraft. The test accuracy is better than 4.8% for the aerodynamic forces in the longitudinal direction, higher than 6.2% for the moments, and more than 8.7% for the longitudinal captive trajectory. The new test technique can meet the requirement of multi-body separation simulations with large position and attitude changes during the two-stage separation process of hypersonic aircraft.