Synchronous Switch Damping （SSD） technology based piezoelectric semi-active vibration control approach can suppress the structural vibration efficiently with relative lower energy consumption， through using the synchronous switches and the equiva lent LC oscillators in control circuits， synchronously inversing the piezoelectric voltage and making it always in the same phase with the structural vibration speed. However， the allowable operation voltage ranges of common piezoelectric driving elements， such as piezoelectric stacks and macro fiber composites， are asymmetric. Hence the symmetrical inversion of SSD approaches is hard to make full use of the electromechanical conversion performance of piezoelectric elements. Therefore， this paper proposes a novel SSD approach based on the bidirectional piezoelectric effect， which maximizes the energy efficiency of the control system and fully matches the electromechanical conversion potential of piezoelectric elements. The approach is realized through the operation of energy injection when the piezoelectric voltage is positively inversed and energy extraction when it is negatively inversed. The working principle of the proposed SSD method is introduced， the vibration attenuation model of the piezoelectric structure under the asymmetric inversion condition is derived， the practical asymmetric inversed SSD control circuit is implemented and the all the results are validated by the experiments. The obtained results show that the proposed SSD method can adaptively adjust the posi tive and negative inversion factors of the piezoelectric voltage by controlling the duty cycle of the energy injection switch and the equivalent load of the energy absorbing circuit， finally achieve a high energy-efficient structural vibration attenuation effect.