The invention discloses a treating system for plasma tail gas of a melting furnace. The treating system comprises an alkaline-liquor pool, a semi-drying acid-removing device, a dust removing device, an absorbing device, a spraying and washing device, a heating device and a reaction device, wherein the semi-drying acid-removing device can be used for suctioning alkaline liquor in the alkaline-liquor pool and carrying out atomized contact between the alkaline liquor and flue gas to be treated; the dust removing device is used for removing dust of waste gas passing through the semi-drying acid-removing device; the absorbing device is used for absorbing small dusts and partial gas in the waste gas passing through the dust removing device; the spraying and washing device is used for removing redundant dusts and acid gas in the waste gas passing through the spraying and washing device; the heating device is used for heating the waste gas treated by the spraying and washing device; and the reaction device is used for carrying out catalytic treatment on the waste gas treated by the heating device. The treating system disclosed by the invention has the advantages that the solid-waste plasma melted tail gas can be purified, and high-efficiency capture for harmful substances such as the acid gas, nitric oxide, dioxin and radionuclide is realized.