Abstract: Based on strain energy equivalency, the background response equivalent static wind load of large span roofs is derived. It solves the matter that numerous structural response control objects should be considered in calculating the equivalent static wind load of large span roofs, and gives a clear physical meaning for the equivalent static wind load. This establishes the relationship between the structural strain energy and fluctuant wind loads. Finally, the method is used to the back equivalent static wind load analysis of the China National Stadium roof structure. The results illustrate that the method proposed in this paper is effective.