An　electrostatic　capacitor　for　energy　storage　is　an　important　basic　component　of　pulse　power　electronics.　The　electrical　breakdown　strength　(E-b)　of　normal　ferroelectrics　is　low,　which　limits　their　application　in　dielectric　energy　storage.　Constructing　a　0-3-type　composite　dielectric,　that　is,　introducing　an　insulating　metallic　oxide　into　the　ferroelectric　matrix,　can　greatly　enhance　E-b.　Unfortunately,　an　intergranular　secondary　phase　typically　forms　that　causes　large　attenuation　of　the　dielectric　constant,　which　leads　to　limited　improvement　of　energy　storage　performance.　In　this　work,　a　composite　ceramic　with　an　intragranular　segregation　structure　was　intentionally　designed　using　the　BaTiO3-BaZrO3-CaTiO3　(BCZT)　system　as　an　example.　Compared　with　those　of　a　BCZT　solid　solution　without　a　secondary　phase　and　a　BCZT　composite　with　a　grain-boundary　secondary　phase,　the　rationally　designed　BCZT　composite　with　an　intragranular　secondary　phase　delivered　a　large　recoverable　energy　density　of　5.86　J/cm(3)　and　high　efficiency　of　86.7%　at　a　moderate　electric　field　of　550　kV/cm.　Such　performance　was　achieved　because　the　intragranular　segregation　structure　displayed　delayed　saturation　polarization　with　a　high　E-b.　This　microstructural　engineering　strategy　is　generally　applicable　to　optimize　composite　dielectrics　to　meet　the　demands　of　high-performance　energy　storage　capacitors.