A liquidsolid extraction column with an expanding tower head was constructed to study two-phase countercurrent fluidization processes. A composite solvent of pentane and hexane denoted as TU-A was used as the continuous phase, and glass beads were used for the dispersed phase. Numerical simulations were performed based on the particle trajectory model of the EulerianLagrangian method to obtain the velocity field of the liquid and the concentration distribution of the solid particles inside the extraction column. The simulation method was previously confirmed by experiments. The operating zone and flooding area of the extraction column were determined by simulations. The results showed that the operating zone could be greatly increased by expanding the tower head, especially for small-particle systems. This study is very conducive to the industrial design and application of liquidsolid countercurrent extraction processes.