Bubble column reactors are often operated under elevated pressure. However, the significant effects of pressure are not well understood. This work aimed to simulate the bubble column operated at elevated pressure by computational fluid dynamics (CFD) coupled with the population balance model (PBM). The effect of the pressure on the bubble breakup was considered based on the mechanism of internal flow during bubble deformation and breakup. For the drag coefficient of bubble swarms, both the hindering effect of small bubbles and the wake accelerating effect of large bubbles were taken into account. Good predictions were obtained concerning the effect of the operating pressure on the gas holdup in both the homogeneous and heterogeneous regimes, especially the significant increase of the gas holdup and decrease of the bubble size at elevated pressure. These results showed that the CFD-PBM coupled model was promising for further simulation of the bubble column under complex operating conditions. (C) 2017 Published by Elsevier Ltd.