The invention relates to a preparation method for electroactive aniline oligomer-modified graphene. The preparation method comprises the following steps of: reducing graphite oxide by a reducing agent, cooling the reduced graphite oxide to the room temperature, centrifuging and drying the cooled graphite oxide to obtain the reduced graphene; ultrasonically dispersing the reduced graphene and the aniline oligomer into an organic solvent; adding dicyclohexyl carbodiimide and 4-dimethylamino-pyridine to the mixed solution; stirring and heating up the mixture for reacting; washing the mixture by a plurality of times by using acetone, alcohol and distilled water in sequence after the reaction is completed; and drying the mixture to obtain the aniline oligomer-modified graphene; doping the aniline oligomer-modified graphene by hydrochloric acid or dodecylbenzene sulfonic acid to obtain the electroactive aniline oligomer-modified graphene. The preparation method has the beneficial effects that the solubility in the organic solvent is improved and the specific capacitance reaches 160 F/g, so that the electroactive aniline oligomer-modified graphene has a broader application prospect in the fields such as super capacitors, solar cells and the like.