A developed three-fluid computational fluid dynamics model was used to investigate the three-phase system in a polyethylene industrial fluidized bed in condensed mode. This model was incorporated with a liquid vaporization modeling scheme comprising heat transfer model, droplet vaporization model, and population balance model to describe liquid evaporation. Numerical results demonstrate that liquid vaporization affects gas velocity distribution, thereby influencing the flow structure. With increasing condensed-liquid contents, the bed temperature gradient at the bed bottom increases and the overall bed temperature decreases. The vaporization rate increases with increasing droplet Sauter mean diameter. Hence, the influence of liquid vaporization is sensitive to droplet diameter.