Operating a fluidized bed at elevated pressure is typically used to intensify processes. The effects of pressure on bubble behavior have been extensively studied; however, the gas flow distribution and particle dynamics are much less studied due to difficulties in measurement. In this work, CFD-DEM simulations are conducted to study hydrodynamics in a thin rectangular fluidized bed at pressures increased from 1 bar to 10 bar. The important findings can be summarized as follows. With an increase of pressure, the bubble size and pressure fluctuations decrease. With increasing pressure, the percentage of visible flow of the rising bubbles increases, while the percentage of the gas throughflow through bubbles decreases. At elevated pressures, the solid flow flux and mixing rate are increased. Finally, the reasons of the influence of pressure on fluidization characteristics are explored in view of the increased inertia force on particles and the increased differential pressure on bubbles. (C) 2020 Elsevier B.V. All rights reserved.