Small furnace cover of electric furnace and preparation method thereof

The invention relates to an improvement of a small furnace cover of an electric furnace and a forming method thereof. The small furnace cover of an electric furnace is characterized in that annular passages which are divided into a plurality of layers in the upper and lower parts and have different radial sizes are arranged on the thickness surface of the furnace cover around an electrode hole in advance, wherein the annular passages are provided with outer connecting pipes extending out of the furnace cover. When in use, cooling air is filled in the passages continuously so as to reduce the temperature of the furnace cover and form a layer of continuous high-viscosity slag protective layer on the working surface of the furnace cover; the temperature reduction prevents the furnace cover from being damaged resulting from heat spalling and structural spalling by great temperature difference when the small furnace cover is removed; besides, the furnace cover made of the same materials has a service life prolonge