The invention discloses a coal slurry oil fuel engine oil composition, which adopts polyinternal olefin and oil-soluble polyether as base oil, and cooperates with various composite additives, which include anti-wear agent, anti-oxidation and anti-corrosion agent, anti-foaming agent, viscosity Index improver, metal deactivator, friction modifier, rust inhibitor, detergent, dispersant, oily agent, antioxidant, antiwear agent. The engine oil composition of the present invention has excellent cleaning and dispersing effects, prevents piston rings from sticking and keeps the engine clean; excellent viscosity-temperature characteristics, excellent alkali number retention, oil viscosity growth ability, and can inhibit the formation of black sludge , make the engine cleaner; good high-temperature oxidation stability, high shear stability, rubber compatibility, good low-temperature startability, excellent fuel economy, no corrosion and rust on moving parts, and ensure sufficient oil quality Oil film strength reduces wear and evaporation losses.