Abstract: Aiming at the problem of narrow sound isolation bandwidth in traditional membrane-type acoustic metamaterial (MAM), we design a lamellar composite mass MAM structure, analyze its sound isolation characteristics using the finite element method, introduce a piezoelectric resonance circuit, obtain the sound isolation curve for the piezoelectric lamellar composite mass MAM structure, and conduct experiments for verification. The results show that the lamellar composite mass MAM structure has an obvious advantage in sound insulation bandwidth. Compared with lumped mass blocks in the 0-1000 Hz band, the average sound insulation is improved by 5.97 dB. Additionally, as the bending stiffness of the mass sheet increases, the sound insulation bandwidth of the metamaterial increases, and the peak value shifts to higher frequencies. The lamellar composite mass MAM structure containing piezoelectric material utilizes the circuit to generate reverse output voltage at the second sound insulation valley band, causing the piezoelectric sheet to produce a reverse force. This results in bending deformation due to the reaction force, leading to vibration displacement in the opposite direction of the intrinsic modes of the membrane, thereby exhibiting negative equivalent mass characteristics and resulting in a second acoustic isolation peak, effectively broadening the acoustic isolation bandwidth.