Abstract: To clarify the flow characteristics of pulverized coal and oil shale particles,the different operating conditions of these irregular fine powder were investigated in this study base on a set of circulating fluidized bed cold model test equipment with diameter of 400 mm and 300 mm.Meanwhile,the fluidization characteristics of pulverized coal and oil shale particles were also compared.The results show that the initial fluidization velocity of the oil shale powder and pulverized coal are about 0.043 m/s and 0.023 m/s,respectively.The small particle take-out velocity of oil shale powder and pulverized coal are about 0.7 m/s and 0.6 m/s.Likewise,the velocity of the large particles take-out velocity of two kinds of materials are about 1.4 m/s.Additionally,the bed density decreases along the bed height when the apparent gas velocity of the bed layer is between 0.1 m/s to 0.7 m/s.In that case,the density of oil shale bed is between 800 kg/m~3 and 350 kg/m~3,and the density distribution of pulverized coal bed is ranging from 750 kg/m~3 to 300 kg/m~3.With the increase of the height of the riser and superficial gas velocity,the density of bed layer in the riser decreases from the bottom to the top,and it demonstrates a certain fluctuation similar S shape.In addition,the density of the bed layer in the riser is between 20 kg/m~3 and 110 kg/m~3.