In the framework of coupling surface/interface theory, a self-consistent scheme of effective field method is proposed to solve the dynamic electro-elastic properties of piezoelectric nanocomposites. The piezoelectric matrix with randomly distributed piezoelectric nano-fibers is reduced to the problem of an effective piezoelectric medium with a typical piezoelectric nano-fiber. The effective wave number and piezoelectrically stiffened elastic modulus are obtained on the basis of the derived imperfect interface conditions around the piezoelectric nano-fiber. Analyses show that the energy at the surface/interface shows significant effect on the dynamic electro-elastic properties, and the effect under different incident frequencies is discussed in details.