The Cu2+ in the drinking water has a very serious impact on human health and social ecology. Many countries have the policy on the Cu2+ concentration limitation in drinking water and the industrial Cu2+ emission standards for the treated wastewater. Scientists have developed many methods to remove Cu2+ from wastewater. Among all the adsorption method is widely used due to its high efficacy, feasibility and low cost. The adsorbent is critical to achieving superior Cu2+ removal result. In this paper, Fe3O4/carbon-graphene oxide nanocomposites (Fe3O4@C-GO) were prepared by a hydrothermal method. The Fe3O4@C-GO is the main absorbent to Cu2+ through chemisorption. The specific surface area of Fe3O4@C-GO dramatically increases from 16 m2/g of Fe3O4@C to 62 m2/g, which expands the Cu2+ absorption capacity up to 350 mg/g. Fe3O4 nanoparticles with about 12 nm in diameter are uniformly encapsulated in the C-GO matrix, and therefore the Fe3O4@C-GO can be easily separated from the solution via magnetics. This adsorbent is also very easily recovered by an external magnetic field from the treated wastewater and has high reusability.