A fire-resistant self-flow castable relates to the field of fire-resistant materials, and is composed of, in parts by weight, 60-85 parts of a fire-resistant main material, 5-20 parts of alumina micro powder, 3-10 parts of pure aluminate cement, 3-10 parts of an expanding agent, 0-3 parts of fine silicone powder, and a water reducer accounting for 0.1-0.5% by weight of the above compositions, wherein the fire-resistant main material is one or two of corundum and alumina, the expanding agent is one or more of fused magnesia, kyanite and quartz sand, and the water reducer is one or more of polyethylene glycol, polycarboxylate water reducers and dispersive alumina. According to the fire-resistant self-flow castable, based on reasonable distribution of granules and fine powders in the castable, by choosing appropriate water reducer, additives and other components, the fluidity of the self-flow castable is substantially improved, and a casted body is reduced in porosity and improved in strength.