The invention provides a preparation method of a magnetic-
functionalized graphene composite material, and relates to preparation of a 
graphene composite material. According to the invention, the preparation method is simple, the 
raw material is easily obtained, and the industrial production is easy; the prepared magnetic-
functionalized graphene composite material has superparamagnetic property and is higher in saturated 
magnetization; and the 
graphene carrier is good in 
conductivity, and loaded ferroferric 
oxide nano particles are uniformly distributed, are small and are good in crystallizability. The preparation method comprises the following steps of: matching ethanediamine and water into a mixed 
solvent, then ultrasonically dispersing 
graphite oxide and iron acetylacetonate in the mixed 
solvent, and obtaining ethanediamine / dispersion of the 
graphite oxide and the iron acetylacetonate; transferring the ethanediamine / dispersion of the 
graphite oxide and the iron acetylacetonate into a reactor lined with 
polytetrafluoroethylene for reaction and obtaining 
solid products; and cleaning the 
solid products, collecting the products with a 
magnet, 
drying and obtaining the magnetic-
functionalized graphene composite material.