The invention provides a black zirconium oxide ceramic and a preparation method thereof. The preparation method comprises the following steps: sanding mixed slurry containing oxide, a dispersant and water to obtain sanded slurry, mixing the sanded slurry with a bonding agent, and sequentially granulating, moulding, debinding and sintering to obtain a primary ceramic, and then performing a reduction reaction on the primary ceramic at 1350-1550 DEG C to obtain the black zirconium oxide ceramic. With the preparation method, the particle sizes of raw materials are reduced by adopting a sanding technology, so that the mass transfer distance between particles is shortened and the mixing uniformity between the raw materials is improved; the dense primary ceramic is obtained through granulation and sintering, and the chemical valence of titanium is changed in the reduction reaction of the primary ceramic, so that the transition track of electrons changes therewith, an absorbed band changes correspondingly, and thus the white ceramic becomes a black ceramic. Results of the embodiments show that the black zirconium oxide ceramic has the blackness value of 110-200 and uniform color distribution.