A moving granular bed with a dual-layer particle structure was designed on the basis of the segregation performance of binary particle flow, and the stratification characteristics of the filter area was studied by using experiment and simulation methods. The results show that the segregation degree (SD) in the filter area is related to the inclined groove length (L) and the binary particle size ratio (gamma); specifically, the SD increases with the increase in the L and the gamma. When the SD reaches the maximum, a significant dual-layer particle structure appears. On this condition, the SD no longer rises with the increase in the gamma or the L. When the SD reaches the maximum, the thickness percentage of the coarse particle layer in the filter area is approximately equal to the mass percentage of coarse particles in the mixed particles. (C) 2020 Elsevier B.V. All rights reserved.