An active vibration reduction system has been developed to solve pitch vibration problems of the force test models in transonic wind tunnel. The system, which uses piezoceramic actuators mounted into the active adapter at the sting top with balance signal as input and velocity feedback algorithm, can suppress the model vibration in an actively controlled way by exploiting the resonance properties of the model/balance/sting system. Ground test results show that the active vibration reduction system increases the first-order and second-order damping ratios of the model/balance/support system by 20.8 times and 12.8 times respectively. It is shown that vibration amplitude of normal force and pitching moment decreased by 71.0% and 57.5% respectively in wind tunnel test results. The wind tunnel test results also reveal that the active vibration reduction system has relatively little influence on the aerodynamic coefficient. In addition, the active vibration reduction system has also been verified in wind tunnel tests of multiple models, showing good vibration reduction performance and model adaptability.