Aiming at the problem of the drag force change in turbulent fluidization system of phosphogypsum particles, on the basis of experiments, considering the existence of nonuniform structures which would influence gas-solid drag force, 2D fluidized bed was simulated using the Gidaspow drag model modified by correcting factor φ. By comparing the simulative results of the Gidaspow model under different φ values with the experimental results, the influence of the changing φ on the simulative results and the variation characteristics of drag force in turbulent fluidization system of phosphogypsum particles with different gas velocities were studied. The results showed that particles aggregated obviously along the horizontal direction in the experimental system, which reduced the drag force between gas and solid phase, the Gidaspow model overestimated the drag force and had a poor prediction capacity on the turbulent fluidization characteristics of phosphogypsum particles. The introduction of appropriate φ can significantly improve the simulative accuracy of Gidaspow model on bed expansion, pressure drop and non-uniformity of the system. The simulative results reflected that the smaller the φ value, the smaller the bed expansion, the more heterogeneous the particle concentration distribution in the bed, and the greater the fluctuation of the bed pressure drop were. As the gas velocity increased (0.144~0.240 m/s), the degree of particle aggregation along the horizontal direction intensified and the value of φ decreased nonlinearly (0.31~0.24). The non-uniformity of fluidization system increased with the increase of gas velocity, the particle concentration was higher near the side walls and lower at the center, a large gradient of particle concentration existed along the radial, ring-core structures appear near the walls on both sides, and the symmetry of flow field distribution was poor.