There is provided a method and an apparatus for treating return ores using plasma, capable of treating sintered return ores generated in a sintering process in a steel maker or return ores (iron ores) employed in other ironmaking process such as FINEX. The method of treating return ores using plasma includes: providing return ores sorted out by a sorting process; and bonding the return ores by fusing and agglomerating the return ores using plasma. Also, an apparatus for treating return ores using plasma includes a plasma heating device used to fuse and agglomerate sorted return ores. The return ores of a predetermined grain size are fusion-bonded and agglomerated using a flame of a plasma heating device. Particularly, the return ores can be treated in a massive amount to enhance productivity of a fusion-bonding process of the return ores. Furthermore, a great amount of sintered return ores generated in the sintering process can be subjected to a fewer number of re-treatment processes.