Hollow granular casting slag for continuous casting production and preparation method of hollow granular casting slag

The invention discloses hollow granular casting slag for continuous casting production and a preparation method of the hollow granular casting slag. The casting slag comprises 31-37% of CaO, 19-24% of SiO2, 2-6% of Al2O3, 0-3% of MgO, 5-7% of F, 11-15% of Na2O, 8-12% of MnO2, 0-4% of Fe2O3, 6-7% of Si and not more than 3% of impurities. The preparation method comprises the following steps: preparing materials, a heat generating agent and an oxygen supply agent from dry-type mixed casting slag; the heating agent is silicon powder, and the oxygen supply agent is MnO2; adding water into the pulping container and adding the materials for pulping; and pumping into a low-speed stirring container for low-speed stirring, high-pressure atomization and hot air drying to form the hollow granular casting slag. The components and the form of the casting slag are optimized, so that the casting slag is fully combusted, the good heating value is kept, the casting blank slag inclusion defect caused by metal residues is avoide