An energy-saving vacuum double cavity holding furnace comprises a 
vacuum furnace shell mechanism, a heating mechanism and a degassing 
crucible mechanism, wherein the 
vacuum furnace shell mechanism is provided with a furnace shell, an inner shell, reinforcing ribs, a furnace cover, a sand injecting opening and a furnace bottom, wherein a vacuum cavity is formed between the inner shell and the furnace shell, the heating mechanism is provided with an 
electric heating wire, a power distribution box, magnesia and a thermocoupler, and the degassing 
crucible mechanism is provided with a 
crucible, a degassing 
brick, a gas inlet tube and a degassing control valve. The temperature of the heating mechanism and the temperature of the degassing crucible mechanism are preserved through a 
vacuum furnace sleeve, the thermal insulating effect is improved, heat of the crucible is directly conducted through the magnesia filled into the periphery of the 
electric heating wire, the 
working temperature on the surface of the 
electric heating wire is lowered, the 
temperature difference between the electric heating wire and the crucible is balanced, and the service life of the electric heating wire is prolonged. The carbon 
fiber reinforcing ribs arranged in the crucible are adopted to effectively prevent fracture of the crucible; the degassing 
brick arranged on the bottom of the crucible is adopted to replace the rotor degassing procedure, the degassing effect and the degassing efficiency are improved, and energy and cost are saved.