Abstract: The scale model of a large-span structure with rhombus hyperbolic-paraboloid roof was designed. A rigid model test under the action of a downburst was carried out. The wind pressure characteristics of rhombus hyperbolic-paraboloid roof under the action of downburst were investigated by the test. The influence of the radial distance and the wind direction angle on the average wind pressure in different areas on the roof was investigated. The experiment results show that: The maximum regional average wind pressure coefficient occurs when the radial distance is 1.25D_jet (D_jet is the spout diameter) and the wind direction angle is 0°; As the radial distance increases, the average wind pressure coefficients of windward firstly increase fast and then decrease, the coefficients in other areas increase first and then tend to be stable; The wind direction angle greatly affects the average wind pressure of each area. The maximum average wind pressure is generated on the roof when θ=0°and the change gradient of wind pressure in the windward is large; The wind load shape coefficients of the corner areas and the edge areas of the roof are both large, and the maximum value reaches −2.75.