A laboratory water medium fluidized separator (WMFS), which is 0.06 m in diameter and 1.5 m high, was designed based on fluidization technique and the principle of hindered settling in hydrodynamics. Then the separation principle of WMFS and the construction of the separation system were introduced. The coarse slime as feed is fluidized by upstream, and is separated according to the different settling velocities (terminal velocities) of the coarse slime in WMFS. The water flow pattern in WMFS was simulated by using CFD software, and the data were analyzed in theory. Finally, the experiment results show that the fluidization technology can be efficiently used in beneficiating coarse slime of -1mm+0.25mm with an Ep value of 0.074.