This study reconstructed porous structure and numerically evaluated permeability properties over several green sinter bed samples by applying X-ray computed tomography (XCT) and orthogonal array tests together. Contributions of three factors including moisture, hydrated lime and magnetite concentrate on experimental Japanese Permeability Units value and XCT-simulated absolute permeability coefficient were analyzed and compared. Results portray that pore network model is helpful to extract the pore distribution and topology in green sinter bed, the observed increase in green bed permeability is attributed to the increase of pore radius, throat radius and throat length, rather than tortuosity. The optimum combination for improving green bed permeability is 7.8% moisture, 4% hydrated lime and 0% concentrate. Moisture and hydrated lime factors are the more effective parameters on bed permeability while concentrate factor is insignificant, since those binders have different mechanisms in determining the outcome granule size distribution and strength, resulting in various pore properties. (C) 2020 Elsevier B.V. All rights reserved.