In this paper, the motion of a water vapor bubble rising in molten lead-bismuth eutectic (LBE) was simulated. The force state of the bubbles before and during the rising process was discussed, explaining the mechanism of bubble deformation and development. The rising terminal velocities of 8 mm, 10 mm and 12 mm bubbles at 200 °C calculated by VOF model were approximately 0.20 m/s, 0.22 m/s and 0.23 m/s, respectively. Combined with the results of numerical calculations, the terminal velocities of the bubble were corrected using three drag force models. It was found that the corrected terminal velocity of the bubbles increases with an increase in the bubble diameter. Further, the acoustic radiation phenomenon during bubble rising was discussed. The study provides theoretical guidance for accident process analysis of steam generator tube rupture (SGTR) in advanced nuclear systems.