The Graphene/Fe3O4/FeSiAl composite was prepared by hydrothermal method. Crystal phase, microstructure and wave absorbing property of the Graphene/Fe3O4/FeSiAl composite were characterized by XRD, Raman, SEM, FTIR and PNA. The results shown that graphene oxide was reduced to graphene by hydrothermal method. And FeSiAl magnetic flakes were coated by graphene and Fe3O4 particles evently. The absorbing material with both magnetic loss and dielectric loss can be realized by composite of flaky and granular. As the mass ratio of graphene oxide with FeSiAl increases, the effective absorption band (RL<-10 dB) of graphene/Fe3O4/FeSiAl composites is moved to higher frequency, which is positive for the application of the absorbent material in the high frequency band.