The invention relates to castable for ladle and a preparation method thereof, and belongs to the technical field of ladle. The castable for the ladle comprises the following raw materials by weight percent: 48 to 77 percent of sintered corundum mullite, 13 to 27 percent of high-aluminum auxiliary materials, 9 to 15 percent of 95 sintered magnesia, 2 to 5 percent of spinel cement, 1.5 to 3.5 percent of silica fume and 0.1 to 0.25 percent of additives. The castable for the ladle has advantages that compared with the traditional ladle castable, the anti-scouring performance and anti-erosion capacity are excellent, the running period of the ladle tends to be fixed, and the schedulability of the ladle repairing time can be improved.