Yttria-stabilized zirconia (YSZ) powder was synthesized by hydrothermal method using yttrium nitrate hexahydrate and zirconium oxychloride as yttrium and zirconium sources, respectively. Then, YSZ bulk material was prepared by spark plasma sintering (SPS) method using the obtained YSZ powder as raw material. The effects of sintering temperature and sintering pressure on the microstructure, Vickers hardness, fracture toughness and other mechanical properties of the bulk materials were studied. The results show that pure YSZ powder can be obtained by hydrothermal method when the content of yttrium is 10%. With the increase in SPS temperature and pressure, the density of YSZ bulk material is gradually increased, and YSZ bulk with a porosity of only 2.6% is prepared at 1400 ℃/50 MPa. With the increase in sintering temperature, the Vickers hardness, nano-hardness and elastic modulus of the bulk material are first increased and then decreased. The increased sintering pressure is conducive to the improvement of the mechanical properties of the bulk material, and the maximum values will be reached at 1400 ℃/50 MPa, when the Vickers hardness, nano-hardness and elastic modulus are 13.11±0.2 GPa, 15.67±0.21 GPa and 350.43±6.19 GPa, respectively. The fracture toughness is decreased first and then increased with the increase in sintering temperature, while decreased with the increase in sintering pressure, which reaches the maximum of 5.4±0.27 MPa·m^1/2 at 1400 ℃/20 MPa.