The invention is an internal-combustion engine special nano alloy lubricant additive and its making method, using general lubricant as basal material and adding in a proper quantity of metals like Sn, In, Pb, Bi, Pt, Zn, Pd, etc to prepare nano alloy powder, portioning according to lubricant 80-90% and nano alloy powder 10-20%, heating, roll-milling, depositing, high-shear emulsifying and purifying and making a novel nano alloy lubricant additive special for internal-combustion engine, environmental-protection, energy-saving, synergistic, life-prolonging. It can be applied to various types of internal-combustion engines in various different types of motor vehicles, engineering machineries, generator sets, railway internal- combustion engines, water transport ship facilities and military power facilities, and can obviously improve the technical indexes such as power, economy, discharge, durability.