This paper introduces in detail the construction organization design of the roof steel truss structure of a project, which adopts the construction method of loose assembly and bulk construction. The contents include: preparation basis, project overview, detailed design of drawings, processing and manufacturing of steel structures, preparation before construction of steel structures, construction of steel structures, welding of steel structures, unloading scheme of steel structures, construction requirements of high-strength bolts, painting of anti-corrosion and fireproof coatings