We develop a one-dimensional model of a composite of 1-3 connection subjected to hydrostatic loading. We obtain the effective modules of composites which depend both on the modules of piezo-ceramics and on the polymeric filler. We consider a problem of the efficient characteristics and their dependence on the shape of the ceramic columns, their dimensions, and location in the composite. Based on the results of analysis of the parametric surfaces derived, we demonstrate the advantages of application of the piezo-composites if to compare with a pure piezo-ceramics. We present a comparative analysis of the 1-3 piezo-composites subjected to hydrostatic and harmonic loading.