In this work, a non-cohesive and multi-element particle model of discrete element method (DEM) was constructed, which was used in combination with experiments to investigate the particle flow characteristics in retangular hopper equipped with the screw discharging machine. On this basis, different diameter pellets (d(p) = 20 mm, 25.02 mm) with various sphericities (phi = 0.868, 0.985, 1) and particle size distribution (a = 0:1, 0.1:0.9, 0.15:0.85, 0.2:0.8) were selected to examine the effects of sphericity and particle size distribution on the distribution of particle average velocity, motion distance and voidage. Our results showed that as the a increased, the particle average vertical velocity was first decreased and then increased. The motion distance of particles at 1/2 bed height was relatively stable. Furthermore, the average voidage of cylindrical particles was the largest and that of ellipsoidal particles was the smallest. Finally, the specific position of the lag of particle motion is revealed. (C) 2020 Elsevier B.V. All rights reserved.