Abstract: For machinery and equipment, rational use of lubricants can not only increase the service life of the machinery and the stability of mechanical operation, but also greatly improve fuel economy. In terms of industrial lubricant, it is mainly composed of base oil and additives. Among them, the base oil accounts for a relatively large proportion, and its nature determines the nature of the lubricant. The purpose of additives is to make up for some defects and deficiencies in the base oil in lubricating oils to achieve the effect of giving them special properties. For the improvement of lubrication under these two conditions, the most effective means is to use lubricating additives, which can form an effective protective film on the surface of the friction pair to prevent friction and wear caused by the direct contact of the friction pair. For this reason, oil-soluble anti-friction and anti-wear additives are usually added to lubricating oil to improve its anti-wear and anti-wear performance, so as to meet the lubrication requirements of machinery under different working conditions. Among different additives, anti-friction and anti-wear agents are of great significance to the anti-friction, anti-wear and load-bearing properties of lubricants. 　In this paper, a new type of oil-soluble quaternary ammonium phosphate ionic liquid (N₈₈₈₁₆P₄) was synthesized, and the thermal stability of each test sample was analyzed on a thermal gravimetric analyzer. The SRV-V fretting friction and wear tester and surface non-contact optical 3D profiler was used to investigate its tribological performance as anti-wear additive in base oil polyalphaolefin (PAO 10) and compounded with commercial additive zine dialkyldithiophosphate (ZDDP). Results showed that N₈₈₈₁₆P₄ had excellent oil solubility and good compatibility with ZDDP, no obvious stratification and precipitation were observed. The addition of N₈₈₈₁₆P₄ increased the initial thermal decomposition temperature of the PAO 10 composition, and with the increase of the amount of N₈₈₈₁₆P₄ added, the thermal decomposition temperature of PAO 10 increased to a certain extent. Under the conditions of room temperature and high temperature (100 ℃), PAO 10 had an obvious biting phenomenon. The addition of N₈₈₈₁₆P₄ with different mass fractions significantly improved the occurrence of this phenomenon. And with the increase of N₈₈₈₁₆P₄, the friction coefficient and wear volume of PAO 10 gradually decreased. The best tribological performance was obtained at the additive amount of 2%, i.e. the friction coefficient of 0.1 and the wear volume reduction of 80%. N₈₈₈₁₆P₄ significantly improved the anti-friction and anti-wear performance of PAO 10. Compared with its compounding with ZDDP, N₈₈₈₁₆P₄ as the additive of PAO 10 showed better anti-friction and anti-wear performance. The tribological performance was best at the additive amount of 1% because the friction coefficient dropped to about 0.1. The extreme pressure performance test showed that the addition of N₈₈₈₁₆P₄ reduced the amount of ZDDP without deteriorating the excellent load-bearing anti-friction performance. The copper corrosion test results showed that N₈₈₈₁₆P₄ was almost non-corrosive, and the combination of N₈₈₈₁₆P₄ and ZDDP significantly inhibited the corrosion of ZDDP. The surface morphology of the worn surface was analyzed by a scanning electron microscopy, energy spectrometer and X-ray photoelectron spectrometer were used to analyze the chemical state on the wear scars. It proved that N₈₈₈₁₆P₄ had complex tribochemical reactions with the metal substrate. The significant effects for ILs on the friction-reduction and anti-wear performances were attributed to the formation of tribofilm containing elements N and P on the worn surfaces.