A vacuum air-quenched tempering furnace, including a furnace body, an inner tank and a furnace cover, the furnace body includes a furnace base, a furnace shell and a furnace lining, the furnace shell is fixed on the furnace base, and the furnace shell is surrounded by a furnace lining The finished furnace, the liner is set in the furnace, the furnace is fixed around the bracket, the electric heating element is fixed on the bracket; the fan device, the hanger, the manual valve, the filling and protective gas pipe, the pump are fixed on the furnace cover. The vacuum tube is characterized in that: the vacuum tube is provided with a solenoid valve. The invention has the advantages of simple structure, reasonable design, good temperature uniformity of the whole furnace, no oxide skin on the annealed workpiece, rapid cooling after heating, greatly improved production efficiency and long service life.