In onder to effectively remove Fe3+ from wastewater, the Fe3O4magnetic fluid was prepared by co-precipitation method. The reduced graphene oxide (RGO) was prepared with hydrazine hydrate as reducing agent. Fe3O4@mSiO2-RGO magnetic mesoporous nanocomposite was synthesized by improved Stöber method. The structure of Fe3O4@mSiO2-RGO was characterized by FT-IR, XRD, BET and magnetic response method. The effects of adsorption time, initial concentration and adsorbent dosage on Fe3+ adsorption were investigated. The results show that when the oscillating reaction time is 40 min, the adsorbent dosage is 24 mg, and the solution concentration is 0.04 mg·L-1, the adsorption rate reach the highest value of 61.8%. Fe3O4@mSiO2-RGO has ideal adsorption-desorption performance of Fe3+. The adsorption process conforms to the quasi-second-order kinetic model, and includes both physical adsorption and chemical adsorption.