Abstract: In order to study the dynamic stability characteristics of the short-blunt shape vehicle, the free oscillation dynamic derivative test method is used to establish the dynamic derivative measurement test technology in the 1.2 m trisonic wind tunnel. The newly designed elastic hinges and bearing hinges solve the problem of elastic support and low-frequency oscillation simulation of the short-blunt shape vehicle, and the newly established test device is used to study the influence of the Mach number, angle of attack, reduced frequency, and shape on dynamic stability characteristics. The newly designed elastic hinge can meet the model support and oscillation requirement under the aerodynamic characteristic condition of the short-blunt shape vehicle in the wind tunnel, and the bearing hinge support can simulate the oscillation frequency close to the actual reduced frequency in the wind tunnel. In the trisonic wind tunnel, the measurement of the pitch derivative of a short-blunt shaped vehicle was completed, and the unstable state points of the pitching were obtained, which provides experimental support for future research on the dynamic stability characteristics of this type of vehicle.