A first method for producing improved coal comprises heating and slaking low-rank coal in an organic solvent to prepare improved coal used in metallurgy; compared with low -rank coal, the improved coal achieves a better softness and fluidity. A second method for reducing ferrum and slag containing non-ferrous metal oxide comprises: preparing particles from the mixture of the improved coal and material containing non-ferrous metal oxide; heating and reducing the particles in a moving-hearth furnace; heating and fusing continuously to form fused reduction product; cooling and solidifying the fused reduction product in the moving-hearth furnace to form a solidified reduction product; discharging the solidified reduction product from the furnace; separating and removing slag by sieve and recovering the metal components as reduced metal. The first method can upgrade the low-rank coal unsuitable for production of a reduced metal by a conventional carbon composite method to an metallurgic improved coal suitable for the carbon composite method; and the second method can be used for preparing reduced metal with high quality by mixing the improved coal into the material.