Combining the piezoelectric effect of the piezoelectric material and the band-gap property of the normal metamaterial plate in the low frequency, a novel tunable piezoelectric metamaterial plate is proposed to enhance the vibration isolation capacity. The equation of motion is established according to the Hamilton principle and the finite element method considering the negative proportional feedback control strategy, which is extended to tuning the band-gap characteristics of the piezoelectric metamaterial plate. Based on the results of the propagation surfaces obtained by solving the corresponding eigenvalue problem, the band-gap properties are analyzed. It is found that the active tuning on the band-gaps can increase the total band-gap width. The broaden effect of the control gain on the width of the Bragg scattering band-gap can be enhanced to the utmost by designing a relatively large base-plate thickness. The piezoelectric patch with a relatively small thickness is beneficial to the generation of the wide low-frequency band-gaps considering the control effect.