Ateetered bed separator (TBS)was improved based on the predecessors’ models, andan experiment system was built.A mass of researches on narrow and mixture sizes fraction of coarse coal slime with subtle partition were conducted, a series behavioral parameter values of coarse coal slime’s separation in TBSwere summarized. The results showed that good separation effect can be obtained both at low and high separation density in TBS for coarse coal slime whose size range is 3 to 0.5 mm; the best height-diameter ratio of TBS for this coarse coal slime sample is 3:1; upwelling speed should increase as size’s increasing for narrow size fraction; the smaller the size range of particles is, the better the separation effect is.