This study presents a micromechanics model for analyzing the effective nonlinear responses of a polarized piezoelectric hybrid composite subjected to large electric fields and small strain deformations. The studied hybrid piezocomposite is constructed by unidirectional piezoelectric fibers embedded in a polymeric matrix, which is reinforced by fillers of piezoelectric particles. The fillers are often used to enhance both mechanical and electrical properties of the polymeric matrix. The high electric field inputs result in strong nonlinear responses of piezoelectric materials, which are often the cases in actuator applications. The micromechanical model is derived based on a fiber-unit-cell model consisting of fiber and matrix subcells. The matrix subcells are comprised of particle-unit-cell models. The polymeric matrix is modeled as linear viscoelastic while the piezoelectric constituents are modeled with the nonlinear electro-mechanical coupling response. The simulation results show that the piezoelectric fillers can significantly enhance the transverse responses of the hybrid piezocomposite, which is useful for applications of 3-1 operating mode.