In order to reasonably calculate the stress of the steel structure coating under the action of sand erosion, and objectively reflect its distribution characteristics. Based on the theories of contact mechanics and structural dynamics, the expression of the erosion load when the steel structure coating is eroded by wind sand is established, and the stress calculation formula of the steel structure coating under the erosion load is derived by using the potential theory. At the same time, combined with the characteristics of wind-sand flow in the northwest region, the stress distribution law at different positions of the steel structure coating was studied. The research results show that the thickness of the topcoat and intermediate paint of the coating should be within the range of 165-210 μm and 145-165 μm, respectively. The topcoat should have good tensile, compressive and shear resistance to prevent surface cracking and plastic yielding of the subsurface layer; the shear and compressive strength of the intermediate paint should be no less than 250 kPa and 800 kPa, respectively. The minimum windward area of the steel structure building should be as perpendicular to the wind direction as possible to reduce the erosion damage to the steel structure building. Under the action of wind and sand erosion, the steel structure coating should be set to three layers of primer, intermediate paint and topcoat, and the thickness of the primer, intermediate paint and topcoat should be increased in sequence; the compressive and shear strength of the topcoat both are better than intermediate paint and primer to prevent surface cracking and subsurface plastic yielding.