The invention provides a plasma melting furnace. The plasma melting furnace comprises a furnace body, a cathode heating system located on the top of the furnace body, and an anode heating system located at the bottom of the furnace body, wherein the cathode heating system comprises a hollow graphite electrode. According to the plasma melting furnace, hollow graphite is adopted by the cathode heating system as the electrode, the electric arc can be compressed, the electric arc temperature can be increased, burning arc stability and arc column orientation can be enhanced, arc deviation can be prevented, and electric consumption and electrode consumption can be reduced; besides, by adopting the hollow graphite as the electrode, water cooling is not needed, the heat loss is small, accordingly, the electric-thermal conversion efficiency is high, and the operation cost of ash and slag treatment is reduced; and in addition, no water is leaked into the plasma melting furnace, so that the safety is higher.