An apparatus for recovering valuable metals and manufacturing multifunctional aggregate from slag. The apparatus includes a slag reforming processing pot 10 in which molten slag discharged from a converter or an electric furnace is stored, a reducing agent introducing part 20 which introduces a reducing agent into the slag reforming processing pot from above, the reducing agent recovering valuable metals from the molten slag, a reducing agent inflow part 25 which inputs a reducing agent into the slag reforming processing pot through a lower portion of a side of the slag reforming processing pot, the reducing agent recovering valuable metals from the molten slag, and cooling units 30 and 40 which create bubbles and perform controlled cooling in order to convert the molten slag, from which the valuable metals are recovered, into a light material having a porous structure.