The invention relates to the technical field of building construction, in particular to an BIM-technology-based steel net rack positioning and installation construction method. The method comprises the following steps of (1) positioning of a steel net rack; (2) installation of the steel net rack; and (3) three-dimensional scanning and retesting check, wherein the installation process of the steelnet rack comprises the steps of (1) installing latticed derrick pulling bars; (2) installing an elevating device on the latticed derrick pulling bars; (3) rechecking net rack fragments; (4) elevatingthe net rack fragments; and assembling the net rack fragments to form the whole steel net rack. The BIM-technology-based steel net rack positioning and installation construction method is suitable forconstruction of the long-span complex structured steel net rack connected through welding spherical joints, bolt spherical joints and bolts. The construction method provided by the invention is simple. Through the construction method, high-efficiency and accurate construction and dual checking and adjusting can be realized; the adjusting frequency of the installed steel net rack in case of errorsis reduced, the construction efficiency is high, the cost is low, elevating is stable, positioning is accurate, the installation quality is ensured, construction errors and rework are reduced, and the construction progress is ensured.