Abstract： To analyze the effect of vibration force on bubble behavior in a gas -solid fluidized bed, and explore the underlying causes of vibration force in improving the fluid state in a fluidized bed, computational fluid dynamics methods and PBM module of Fluent 14.5 were used to study the characteristic of bubble behavior in a vibro-fluidized bed against the actual experimental results. Through physical modeling, mathematical model updating, meshing, boundary condition setting and the actual test results, it was performed to compare the size distribution and the rising veolcity of bubbles， the bed pressure fluctuation signals and other features changes with vibration force. The results show that the bubble size distribution is more uniform and the large bubbles are less, the diameter of bubbles increases with the bed height without vibration. After joining vibration, there is an uneven size distribution of bubbles in the bed, large bubbles are more. At the beginning of the bubble rising， the diameter of bubbles grows, the rising velocity of bubbles increases and then decreases in the late. The periodicity of bed pressure fluctuation signal increases apparently.

Keywords: vibro-fluidized bed; vibration force; bubble behavior; numerical simulation