Novel fireproof and heat-resistant magnesia brick

The utility model discloses a novel fireproof heat-resistant magnesite brick which comprises a magnesite brick body, a hollow cavity penetrating through the magnesite brick body is formed in the magnesite brick body, an inner supporting frame is fixed in the hollow cavity, a heat storage layer is arranged in the inner supporting frame, and an outer supporting frame of a square ring structure is embedded in the magnesite brick body. Wherein the outer supporting frame is arranged on the outer side of the inner supporting frame in a sleeving mode, a plurality of inner supporting pieces connected with the outer wall of the inner supporting frame in an abutting mode are fixed to the inner wall of the outer supporting frame, a plurality of first fireproof plates arranged at equal intervals are embedded in the upper end face and the lower end face of the magnesite brick body correspondingly, and a first groove is formed between every two adjacent first fireproof plates; a plurality of second refractory slabs which a