A method for separating zirconium oxide/hafnium oxide by pyrometallurgy. The mixture of zirconium oxide/hafnium oxide, carbon and pure bromine react one hour at 650° C., then added to molten salt mixture for rectifying separation, and then maintained two hours at rectifying tower bottom below 357° C., to get the non-target substance; and then maintained five hours at 357° C. to collect the target substance zirconium tetrabromide; the residue in the reactor is retained, then rectification separation is performed in the same device, heated to 400° C. to retain more than five hours, to get hafnium tetrabromide, then the zirconium tetrabromide and hafnium tetrabromide are substituted by magnesium to get the pure zirconium and pure hafnium.