To address the problem that open ore storage yards are highly likely to cause particle dust pollution under the action of external forces，this paper investigates the wind velocity reduction effect of the windproof and dust suppression net on different incoming flows. Specifically，the paper numerically simulates the flow field behind the dust suppression net with the renormalization group（RNG）k-ε model provided by Fluent. Then，it builds a three-dimensional model based on measured data to calculate the velocity distribution on the stockpile surface under different incoming flows. The simulation results suggest the following conclusions：1）After the airflow is combed by the pores of the dust suppression net，an obvious vortex backflow area emerges behind the dust suppression net. It changes the airflow structure on the stockpile surface，thereby effectively reducing the velocity on the stockpile surface. 2）The comprehensive velocity reduction rate is 23.52%. The area of the storage yard covered by the vortex backflow area varies with the direction of the incoming flow. The comprehensive velocity reduction rate differs significantly，and the difference range is 7.69%-50.87%. The attenuation of north-northwest and north-northeast incoming flows is particularly prominent.