The invention discloses a refractory castable and a using method thereof. The refractory castable is prepared by taking silica gel / sol as a binding agent and tartaric acid as an accelerating agent and adopting corundum, activated alumina micro powder, 96% of silicon oxide micro powder, pure calcium aluminate cement, steel fibers and an additive. The refractory castable has the characteristics of good flowability, stable curing, shorter curing time, high demoulding, medium temperature and high temperature strength, good thermal shock resistance and the like, and is an excellent refractory material required by thermal equipment in the industries such as metallurgy, machinery, electricity, petrochemistry and construction and by high temperature kilns.