Abstract: Cationic polyelectrolyte poly(diallyldimethylammonium chloride)(PDDA) was used to modify SiO₂, and SiO₂-PDDA-graphite oxide (GO) core-shell hybrid particles were prepared by electrostatic self-assembly. By introducing SiO₂-PDDA-GO into high-temperature vulcanization silicone rubber (SR)with solution blending method, SiO₂-PDDA-GO/SR dielectric elastomer composites were prepared. Results show that this method can realize GO large surface coating on surface of SiO₂ to prevent GO from self-agglomerating. GO core-shell hybrid particles/SR composites were obtained without in-situ thermal reduction because PDDA can reduce GO, made experimental scheme simple and environmental protection. The dielectric constant of SiO₂-PDDA-GO/SR dielectric composite at 100 Hz increases to 21.53 with 60wt% SiO₂-PDDA-GO which is 11.6 times than SR, and dielectric loss remains at low level. Meanwhile, modulus of composites remains low level. The lateral actuation strain of SiO₂-PDDA-GO/SR dielectric elastomer composites with 60wt% SiO₂-PDDA-GO at 2.48 kV/mm compared with pure SR increases 15 fold under same electric field intensity.