The invention relates to hard polyimide foam modified material, and in particular to a reinforcing and toughening self-setting hard polyimide foam material and a preparation method thereof. The preparation method comprises the following steps: dissolving aromatic dianhydride into a solvent, adding fatty alcohol for carrying out an esterification reaction, adding a catalyst and a surfactant in the solvent after completing the reaction, then sequentially adding modifiers, and uniformly dispersing by adopting an ultrasonic dispersion technology, thus obtaining a foam precursor solution; adding acid anhydride into isocyanate so as to react with the isocyanate, and then adding phosphoric acid, thus preparing and obtaining modified black material; enabling the foam precursor solution to react with the modified black material according to a proportion, immediately pouring the mixture into a mold after stirring, carrying out normal-pressure foam forming, and carrying out self-setting demolding, thus obtaining the reinforcing and toughening self-setting hard polyimide foam material. The reinforcing and toughening self-setting hard polyimide foam material prepared by the invention has high strength, good temperature resistance and very low moisture absorption rate, and can be used as a structural material; a preparation process is environment-friendly and energy-saving, and the technology is simple.