The invention relates to the field of carbon structure production and, in particular, to a method for synthesis of graphene oxide which is widely used in electronics, medicine, pharmacology and construction industries.Provided is a method for synthesis of graphene oxide that includes oxidizing ground graphite with sulfuric acid and at least one oxidizer in a medium of supercritical fluid, wherein the method includes providing a mixture of sulfuric acid and dry ice in an amount sufficient for the mixture to solidify, and a mixture of at least one oxidizer and dry ice, wherein at least one of said mixtures contains ground graphite; introducing the provided mixtures into a high pressure autoclave; and further mixing the reagents.Thus, the claimed invention is a method for synthesis of graphene oxide that allows achieving the technical result consisting in safe production of high quality graphene oxide, wherein the time cost is relatively low and the consumption of sulfuric acid is significantly reduced.