Abstract: As sustainable energy storage and convert device, dielectric capacitors play a non-substitutable role in the sustainable energy systems. The dielectrics are the core of dielectric capacitors. The polymer dielectrics have great potential to be applied in the high energy density capacitors for their high breakdown strength, fast discharge rate and excellent cyclability with self-healing property but the low dielectric constant. The mposite dielectrics combining ceramic counterparts with high dielectric constant and poly(vinylidene fluoride)(PVDF)-based copolymers with high breakdown strength have been developed, which achieved high energy density, low loss and high efficiency. This review introduces the fundamental principles of dielectrics and different types of ceramic/PVDF-based copolymers composites, their development trends are also prospected.