On the basis of experimental research and numerical analysis, a new composite soil nail support technology was successfully designed and constructed for a soil cavern with a gross span of 10.5m and a gross height of 7.07m, and monitoring results and conclusions were presented. Its novelty lies in the use of composite soil nails to support large-span soil caverns, eliminating the secondary permanent lining, breaking through the traditional construction method of caverns, saving cumbersome mechanical equipment and expensive multiple trolleys, making construction convenient and feasible, providing a new type of support method for the construction of large-span soil caverns