High concentrated dust from coal mining is hazardous in that it seriously affects the health of the exposed miners and might also lead to explosion directly or indirectly. In order to effectively control the onsite dust density, we simulated the spray behavior of the dust-settling devices under various operational parameter combinations based on CFD numerical simulations in combination of the orthogonal experimental design. After a comprehensive evaluation, we obtained an optimal parameter combination from the multi-factor analysis and applied it to the working site. The results demonstrated that the concentration of total dust and respirable dust at every measurement point dropped below 80.4% and 81.9% respectively. The working condition was greatly improved and the dust explosion hazards were effectively under control. This study provides a new approach for the structural and parametric optimization of spray dust-settling devices. It yields reliable results using the CFD simulations combined with multi-index orthogonal experiments. (C) 2020 Elsevier B.V. All rights reserved.