Abstract: According to the poor separation effect of the difficult prepared coarse slime with the traditional liquid and solid fluidized bed,a test system mainly with the t hree products liquid and solid fluidized bed was established and applied to the study on the gradual separation process of the difficult prepared coarse slime. A single facto r conducted under the condition of the different parameter was applied to discover the material separation process with the primary separation chamber in the lower chamb er and re-separation in the top chamber. A comparison analysis was conducted on the test results. The study results showed that the bedding pressure and the upflow wate r flow would obviously be affected to the separation and preparation of the material. When the bedding pressure of the lower chamber was 12 k Pa,the upflow water quantit y was 0. 4 m3/ h,the bedding pressure of the top separation chamber was 5 k Pa and the upflow water quantity was 0. 1m3/ h,the ash content of the tail coal would be the highest,the ash content of the cleaned coal would be the lowest and the separation and preparation effect of the difficult prepared coarse slime would be the best.