Composite ductwork is a new type of high-tech composite material consisting of two layers of glass fiber reinforced chloroaluminate magnesium cement panels and a flame-retardant polystyrene foam core. Suitable for renovation and expansion projects with complex old structures and lower load requirements, as well as for large spaces like gymnasiums and libraries with high environmental protection standards. When manufacturing composite ductwork, attention must be paid to the following: the cutting line should be straight, the diagonal length of the ductwork panels should not exceed 5mm, and the cutting line must form a 90-degree angle with the panel surface. If the length of a single section of ductwork is less than or equal to 1250mm, the length L should not exceed 1250mm. During the production of straight pipes, the stepped thermal insulation layer on the side panels should be scraped off; the longitudinal bonding direction of the left and right side panels should be offset by 100mm from the top and bottom panels, the spacing of the binding straps should be 650mm, and 90-degree protective feet should be used at the junction with the four corners of the ductwork.