Jamming of particles is a phenomenon that occurs widely in our daily life and nature. However, the jamming of the polydispersed particle systems, such as sand particles, have rarely been studied and are not well understood. Thus, this work conducted CFD-DEM simulations to study the jamming of a polydispersed particle system with a log-normal particle size distribution. The simulation results show that the jamming probability is strongly dependent on the diameter of the larger particles in the distribution, especially the characteristic particle diameter d(90). The orifice-particle size ratio, used to predict the jamming probability of the polydispersed particle system, can be defined as the ratio of the orifice size D-0 to d(90). The prominent influence of large particles on jamming was illustrated from the view of the particle jamming arch compositions. Moreover, we found that the polydispersed particle jamming arch can form with the defect and avalanche under the fluid flow. (C) 2020 Elsevier B.V. All rights reserved.