The utility model discloses utility model an overflow clean coal desliming grading plant is selected separately to solid fluidized bed coarse coal mud of liquid, including selecting separately hierarchical staving, rhombus locating pin, overflow desliming device. Select separately hierarchical staving by last staving, down staving and base cone constitute, base cone connection suitable for reading staving lower part under, the base cone end opening sets up the tailing valve. Rhombus locating pin sets up under between staving and the base cone. Overflow desliming device comprises oblique staving, flow distribution plate and overflow launder. The sectional area suitable for reading of staving is greater than the end opening sectional area to one side. The flow distribution plate slope sets up the upper portion at oblique staving. The overflow launder sets up around oblique staving top, and the flow distribution plate separates the overflow launder for controlling two parts, and coarse grain thing overflow pipe communicates with each other with half right part of overflow launder, and a particulate thing overflow pipe and an overflow launder left side partly part communicate with each other. Thick clean coal is discharged through the thick clean coal blow -off valve of addendum cone afterbody after the staving subsides to one side, and the desorption ability of overflow to thin mud directly from the overflow launder discharge, has been reinforceed to thin mud, improves the quality of overflow product.