The invention discloses a combined firework conformation body adopting a foamed material, which is used for fixed setting off of device firework inner barrel. The combined firework conformation body comprises a conformation body and barrel holes; the conformation body is processed and formed from foamed material; a plurality of closed barrel holes are formed in the conformation body, in which firework inner barrel can be fixedly connected; the quantity of barrel holes in the conformation body and the shape of the arrangement of the barrel holes are arranged according to the firework setting off requirement; and the outer shape of the conformation body is of a cube, a rounded body, a elliptical body, a fan-shaped body, a triangular body, a polygonal body or a specific body shape; and the conformation body is formed through integral molding. The combined firework conformation body adopting the foamed material has the advantages of simplicity in process technology, lightness, water-proofness, moisture-proofness, vibration-proofness and corrosion-proofness, is suitable for the one-step integral conformation of various firework outer barrels or inner barrels, can be processed into various shapes or specific shapes as needed, and is particularly suitable for mechanical manufacture and process.