The invention discloses a plasma furnace for comprehensively treating solid and liquid wastes. The plasma furnace comprises a furnace body consisting of a top cover, a furnace body and a furnace bottom, wherein a hearth is formed in the furnace body and is divided into a gasifying area and a melting area; a high-temperature refractory fiber layer, a high-temperature insulating layer and an insulating fiber layer are sequentially arranged between the hearth and a casing of the furnace body from the inside to the outside; a solid feeding channel, an exhaust channel, a waste liquid feeding spray opening, a plasma generator installation interface and a discharging interface are arranged on the furnace body. By implementing the plasma furnace disclosed by the invention, the capability of simultaneously treating solid waste and liquid waste can be realized; in addition, the plasma furnace has the characteristics of simple structure, good convenience for detaching and maintaining, high utilization rate of heat and the like.