The present disclosure relates to an azobenzene-graphene metal coordination solar photothermal energy storage material based on metal coordination bonds and a preparation method thereof. The method comprises the following steps: preparing reduced graphene oxide; preparing an azobenzene-graphene material; and preparing an azobenzene-graphene metal coordination solar photothermal energy storage material: dispersing the prepared azobenzene-graphene material in DMF, dissolving a certain amount of metal compound in DMF, adding the DMF solution of the metal compound into the DMF solution of the azobenzene-graphene, taking out the precipitate, washing off metal ions which do not participate in coordination, and drying the obtained product to obtain the azobenzene-graphene metal coordination solar photothermal energy storage material. The present disclosure also relates to a method for improving the solar photothermal energy storage ability of a molecular solar energy fuel, comprising using an azobenzene-graphene metal coordination solar photothermal energy storage material.