The invention discloses a quantitative detection method for the oxidation degree of oxidized graphene and a construction method of a used standard curve. The construction method of the standard curve comprises the following steps of 1) preparation of standard oxidized-graphene samples: a) adding multiple original oxidized-graphene samples with different oxidation degrees into a solvent, soaking, stirring and washing till the pH of pulp is 3-7; b) adding the oxidized graphene obtained in the step a) into the solvent, preparing into oxidized graphene pulps with same solid content and obtaining multiple standard oxidized graphene samples with different oxidation degrees; 2) acquisition of A230/A600: determining the absorbance of the standard oxidized-graphene samples under the room temperature at the positions with the ultraviolet wavelengths being 230nm and 600nm, calculating the ratio between the absorbance of A230 and the absorbance of A600, namely the A230/A600 value; 3) construction of the standard curve: drawing the standard curve according to the A230/A600 value of every standard oxidized graphene sample and the O/C molar ratio of the original samples.