The invention discloses a multi-layer de-sliming thickener. The multi-layer de-sliming thickener comprises an upper cone (1), a receiving barrel (3), a lower cone (2) and an overflow groove (12). The upper cone (1) is of an inverted-cone shape, a lower distribution plate (5) is arranged at a discharging port in the bottom of the upper cone (1), and an upper sedimentation region is formed inside the upper cone (1). The receiving barrel (3) is arranged inside the upper cone (1) and provided with a feeding pipe (7), and an upper distribution plate (4) is arranged at a discharging port in the bottom of the receiving barrel (3). The lower cone (2) is of an inverted-cone shape, the upper cone (1) is sleeved with the lower cone (2), a grout valve is arranged at a bottom flow pipe (8) of the lower cone (2), and a lower sedimentation region is arranged inside the lower cone (2). The overflow groove (12) is formed in the periphery of an overflow opening of the upper cone (1) and the lower cone (2), and provided with an overflow pipe (13). The thickener has high de-sliming and thickening efficiency, the production capacity per unit area is high, and one thickener can achieve the using effect of performing thickening and de-sliming on two or more sections, and is a good choice for de-sliming in concentrating mills and particularly for selective flocculation de-sliming and thickening operation.