The invention discloses a method for grafting SiO2 nanoparticles with graphene oxide modified epoxy resin. The method comprises the following steps of: mixing ethyl orthosilicate with tetrahydrofuran, dropwise adding hydrochloric acid, stirring at the normal temperature, adding deionized water and sodium chloride, stirring uniformly, separating by using a separating funnel, removing a lower layer clear solution, adding anhydrous magnesium sulfate into an upper layer organic solution, standing over night, and filtering to obtain SiO2 sol; dropwise adding toluene diisocyanate into an ultrasonically-dispersed graphene oxide solution, adding the prepared SiO2 sol, performing suction filtration under reduced pressure, washing a product with absolute ethyl alcohol, and drying to obtain cinereous powder, i.e., SiO2 nanoparticle grafted graphene oxide; and adding the SiO2 nanoparticle grafted graphene oxide into an epoxy resin substrate, and carrying out a curing reaction to obtain a modified epoxy resin condensate. The method has the advantages of simple process, easiness in operating, environmental friendliness, simple equipment, contribution to reducing cost and applicability to mass production.