The invention discloses a die for forming a double-aggregate high-refractory aluminum hot welding bottom plate. The die comprises a lower die base, and a lower die mold core, a silicon sand forming die and a zirconium sand forming die arranged on the lower die base, the silicon sand forming die comprises baffles forming a surrounding closed enclosure and a first cavity body formed by defining of the baffles, and the lower die model core and the zirconium sand forming die are arranged in the first cavity body; and the zirconium sand forming die is located above the lower die model core, a second cavity body in a surrounding closed structure is formed in the zirconium sand forming die, an inner cavity of the first cavity body and the second cavity body forms a first mold cavity of the uppersurface of the formed bottom plate and the middle structure of the bottom plate, and a second mold cavity is formed in the space occupied by the zirconium sand forming die in the first cavity body. The double-aggregate high-refractory aluminum hot welding bottom plate forming die can efficiently and smoothly form the double-aggregate high-refractory aluminum hot welding bottom plate, save the useamount of zirconium sand of valuable refractory materials, solve the production problem that a double-aggregate bottom plate is not prone to forming, and improves the production efficiency and formingeffect.