Accurate resolution of gas dispersion parameters in multiphase flow is crucial for optimizing the performance of fluidized bed flotation. In this study, a gas-liquid-solid three-phase system consisting of compressed air, water, and steel beads was constructed, and the effects of apparent water velocity, apparent gas velocity, static bed layer height, and heavy-phase mass ratio on the bubble diameter and gas content were systematically investigated. The results showed that the minimum value of bubble diameter was 0.56 mm and the maximum value of gas content was 0.1835 at a static bed height of 0.2885 m and a heavy-phase mass ratio of 50%, and a four-factor, three-level mathematical model was further developed by Box-Behnken response surface design, and the analysis showed that the static bed height and the apparent water velocity were the main factors affecting the bubble diameter, with a significance of p<0.05. Finally, the effects of bubble diameter and gas content were established. 0.05. Finally, a prediction model between bubble diameter and multiple factors was established to provide theoretical support for the structural design and industrial application of three phase fluidized bed flotation columns.