Abstract: Due to the maldistribution of coal fluidization, coal leakage may occur inside wind\|box during operation of large\|scale 480t/h CFB or more. In order to improve the fluidization quality of bed materials, the porous model and 3D Eulerian\|Eulerian multiphase model with closure law according to the kinetic theory of granular flow were applied to simplify the wind distributor and to simulate the fluidization characteristics with different pressure losses of wind distributor. The results show that, under the condition of increasing pressure loss of wind distributor, the uniformity of coal fluidization can be improved with the low leakage of coal in windbox. Therefore, during the design of the large\|scale CFB, the structure of wind\|box and size of orifice have to be designed carefully with the increasing of the wind distributor pressure losses properly.