As advanced dielectric materials for the applications in electronics and electrical power systems with the ever-increasing requirements, the polymer-based dielectric nano-composites are brilliantly emerging. However, there are long standing challenges of the unsatisfactory electric breakdown strength and the heat accumulation induced by dielectric loss of composite. In this study, we propose an artificial nano-composite with excellent comprehensive performance by controlling the orientation of one-dimensional (1D) 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 nanofibers (BZCT NFs) and adjusting the interaction between BZCT NFs and poly(vinylidene fluoride) (PVDF) matrix via SiO2 buffer layer. Remarkably, PVDF nano-composite with only 3 vol% aligned BZCT NFs coated by SiO2 (BZCT@SiO2 NFs, 3 vol% Aligned BZCT@SiO2-PVDF) possesses an impressive energy storage performance, including the superior Weibull characteristic breakdown strength (E b) of ~576 kV/mm and the ultrahigh discharged energy density (U e) of ~18.9 J/cm3. Meanwhile, the temperature distribution in this typical composite is more homogeneous according to the test and simulation results. This demonstrated work not only opens a new door to preparing an excellent performance of polymer-based dielectric nano-composites, but also points out a route to the industrialization of energy storage dielectrics.