The invention relates to the technical field of preparation of anticorrosive coatings, and provides a preservative coating with stable dispersibility. A preparation method includes: preparing an ethylene-vinyl alcohol copolymer precursor and performing a heating reaction of combining silane with the ethylene-vinyl alcohol copolymer precursor under conditions of high pressure and constant-speed stirring with graphene oxide modified by a coupling agent, wherein the ethylene-vinyl alcohol copolymer precursor is combined with the coupling agent to form a compact film on the surface of the grapheneoxide, thereby greatly increasing the dispersibility of the graphene oxide, so that the graphene oxide can be dispersed in resin uniformly and stably to form the high-effective graphene hot-melting anticorrosive coating.