Abstract: Graphene has excellent electrical, optical and mechanical properties．Nano-structured materials composed of Mo-Co composite metal oxides could potentially be applied in electromagnetic wave absorption due to their excellent physical properties．In this paper hollow spherical Co₃O₄-CoMoO₄ composite oxide nanomaterial was synthesized by the solvothermal combined calcination method．Co₃O₄-CoMoO₄ as magnetic loss material was combined with graphene for electromagnetic wave absorption test．The composite material was found to have better electromagnetic wave absorption at 2 mm, with minimum reflection loss at −23.45 dB, at an absorption bandwidth of 2.55 GHz．This would be a new type of absorbing material with excellent properties．