Abstract: A method of bottom ash discharging and separating in fluidized beds was proposed by unequal distribution of wind speed,which is based on separation theory of fluidization and difference of particle terminal velocity. A visible cold test-bed was built to evaluate the effects of the pressure distribution,fluidization velocity and particle size distribu- tion on discharging and separating. Experimental results showed that reasonable pressure distribution characteristic re- sulted in particles circulation in the fluidized bed. The increasing ratio between high wind speed and low wind speed led to the better separation effect. However,due to the mixing of fine particles with coarse particles,particle separation effect was greatly reduced by the increasing fine particle volume fraction. Bottom ash discharging with unequal distri- bution of wind speed can realize particle separation.