To improve the mechanical properties and corrosion resistance of water-based epoxy coatings，polyether amine was used to chemically modify the carboxyl group at the edgeof graphene oxide（GO）to prepare modified graphene oxide（AGO）， and modified graphene oxide/waterborne epoxy（AGO/EP） composite coating was prepared by compounding with waterborne epoxy resin. The effects of AGO content on the microstructure，mechanical properties and corrosion resistance of composite coatings were investigated. The results showedthat AGO was uniformly dispersed in waterborne epoxy and had a good interface effect withwaterborne epoxy，forming a certain ordered layered structure，which enhanced the tensile strength and elongation at break of the coating. The low frequency impedance modulus of thewater-based epoxy composite coating（0. 5%AGO/EP）reached 4.47×10⁸ Ω·cm². The addition of AGO effectively inhibit the corrosion of water vapor and salt ions on the steel plate substrate，and the salt spray corrosion resistance of the composite coating was significantlyimproved.