Silane coupling agent was used to modify graphene oxide, and Fourier infrared spectroscopy(FTIR), Raman spectroscopy and X ray diffraction(XRD) were employed to characterize the structure changes of graphene oxide before and after modification. The functional graphene oxide/polyurethane coating and ordinary polyurethane coating were sent to mechanical performance test and simulated wind sand erosion test. The results show that the silane coupling agent is able to successfully modify the graphene oxide by covalent bonding, and the functional graphene oxide has good dispersibility and compatibility in polyurethane; the hardness of the coating increases first and then decreases with the increasing functional graphene oxide content; when the functional graphene oxide content is 05%, the erosion rate of the coating is significantly reduced, and the wind sand erosion resistance performance is significantly improved. After simulating extra strong sandstorm erosion, the service life is longer than ordinary polyurethane coating by at least 08 a.