Electrostatic separation can be used to remove micron-sized catalyst particles from fluid catalytic cracking (FCC) slurry. In this study, simulations were performed with experimental parameters. The distributions of the electric field, slurry flow and particle motion were studied. According to the particle movement characteristics, an effective adsorption region was found in which the particles would be adsorbed on the surface of the fillers. The effect of the effective adsorption region on the electrostatic removal of catalyst particles from the FCC slurry was discussed. The size of the effective adsorption region was inversely proportional to the voltage and ionic carrier concentration. Under the same parameters, the size of the effective adsorption area and the motion of the particles were compared between the experiment and the simulation. The results showed that the numerical simulation results were in good agreement with the experimental results. (C) 2020 Elsevier B.V. All rights reserved.