Abstract: Surface-modified α-zirconium phosphate (α-ZrP) nanosheets were prepared by a one-pot hydrothermal method. The crystal structure and morphology of nanosheets were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, field-emission scanning electron microscopy and transmission electron microscopy, respectively. The dispersion stability of surface-modified α-ZrP nanosheets in poly alpha olefin (PAO-6) base oil was analyzed. By using an oscillating reciprocating friction and wear tester (SRV-Ⅳ), the tribological properties of the surface-modified α-ZrP nanosheets as additive in PAO-6 were investigated. The surface-modified α-ZrP nanosheets had good dispersion stability in PAO-6 lubricating oil. Besides, surface-modified α-ZrP nanosheets as an additive significantly improved the extreme pressure performance and anti-wear property of PAO-6 oil.