Barium zirconate titanate (BaTi0.7Zr0.3O3) ceramics were prepared via spark plasma sintering (SPS) and conventional solid-state sintering (CS). Both samples exhibited single phase nature as confirmed from the X-ray diffraction analysis. Compared with CS sample, more homogeneous microstructure with smaller grain size was observed in the SPS sample, which greatly improved the dielectric strength of BaTi0.7Zr0.3O3 ceramics from 40 (CS) to 170kV/cm (SPS). Although the polarization of SPS sample was lower than that of CS sample under the same applied electric field, the maximum energy storage density was improved to 0.51J/cm(3), which was about 4.5 times higher than that of the CS sample (0.12J/cm(3)). Moreover, finite element simulation on the local dielectric field distribution was carried out, and the effects of microstructure on the dielectric strength were further confirmed.