Dry beneficiation technology of coal with an air dense-medium fluidized bed commenced application lately in China. This paper analyzes the characteristics of gas-solids fluidized beds and basic principles of coal separation, and describes systems for coal dry beneficiation (including raw coal pre-treatment, coal separation, medium solids recovery, air supply and dust removing). Experiments on a 50MTPH air dense-medium fluidized bed system for the dry beneficiation of coal shows that a uniform and stable fluidized bed can be formed with magnetite powder or a mixture of magnetite powder and fine coal as medium solids. The separation performances of the separator were investigated and assessed in detailed. The results indicate that 50 X 6 mm coal can be separated effectively with an E-P value of 0.05. The performance results of this technology are satisfactory.