Abstract: type piezoelectric composites using thickness shear mode (PCMTS) were selected as the cores of the sandwich structure, which can generate the thickness shear deformation and actuate the sandwich structure to give rise to the desired transverse deflection. The actuating principle of the PCMTS cores was analyzed, and the experimental investigations were carried out to evaluate the sandwich beam characteristics featuring the actuation of the PCMTS cores. Meanwhile, the active vibration control of the sandwich beam with the PCMTS cores was studied. The results indicate that, using the PCMTS cores as the actuators, an ideal deflection of the sandwich beam is generated and the vibration of the sandwich beam is suppressed effectively.