High-quality synthetic MgO- -CaO- -Fe2O_ raw materials, reasonable particle size gradation composition, make the product have good sintering and corrosion resistance. The product is easy to construct and has strong integrity. It can be constructed for the first time or can be hot repaired. It is suitable for the construction and repair of high-power electric furnaces, ultra-high-power electric furnace bottoms, furnace slopes and other parts.