The invention discloses a preparation method of slag-corrosion-resistant continuous casting fire-resistant materials, and belongs to the technical field of fire-resistant materials. According to the preparation method, enzymolysis of rice hulls are firstly performed, the rice hulls are soaked by the aid of hydrochloric acid, acid-soluble inorganic impurities are removed, the rice hulls are dried, the dried rice hulls and aluminum powder are mixed, organic materials in the rice hulls are carbonized under the protection state of nitrogen, the carbonized organic materials and parts of silicon dioxide components in the rice hulls react to generate silicon carbide, the aluminum powder and the nitrogen react to generate part of aluminum nitride, the carbonized organic materials without reacting are removed in the air atmosphere environments, residual aluminum powder and oxygen in the air react to generate aluminum oxide, sodium fluoride and aluminum fluoride are added to generate cryolite in a matched manner, a melting point of the aluminum oxide is reduced, calcium oxide and the aluminum oxide form low-melting-point substances, attachment and blocking of the aluminum oxide are avoided, phenol-formaldehyde resin serves as a binding agent, isostatic forming is performed, and a mixture is sintered to obtain the slag-corrosion-resistant continuous casting fire-resistant materials. The preparation method effectively solves the problem that attachment and blocking of the aluminum oxide are easily generated when traditional aluminum-carbonate-type fire-resistant materials are used.