In order to study the effect of microstructure of nano-additive zirconium phosphate (α-ZrP) on its tribological properties,α-ZrP with different morphology and particle size was prepared by adjusting the lyophilization process parameters.The microstructure of α-ZrP was characterized by SEM,TEM and XRD.The effect of the content and crystal types of α-ZrP on the friction and wear properties of paraffin base oil was investigated on the ball and disk reciprocating motion testing machine under different working conditions.The results show that α-ZrP with granular,rod-shaped and lamellar can be obtained by controlling the amount of polyvinylpyrrolidone additive,and the friction coefficient of granular α-ZrP is the minimum under the same conditions.With the increase of freezing rate,the particle size of α-ZrP decreases,and the friction coefficient of α-ZrP also decreases under the same conditions.The lamellar α-ZrP has the best tribological properties at low speed and heavy load condition,while the granular α-ZrP has the best tribological properties at high speed and light load condition.