Lubricating oil for methanol fuel engine and preparation method thereof

The invention provides lubricating oil for a methanol fuel engine, which comprises the following components in percentage by weight: metal detergent 2.2-5.2, ashless dispersant 3.5-6.8, antioxidant and anticorrosion agent 0.5-1.6, high-temperature antioxidant 0.3-0.8, viscosity index improver 6-11, oiliness solvent 2.8-6, anti-foaming agent 120ppm, metal anti-rust agent 0.3-0.7, base oil 62.7-83, demulsifying agent 0.1-0.3, metal extreme pressure anti-wear agent 1.0-4 and pour point depressant 0.3-0.9. The lubricating oil of the invention has functions of preventing wear and rust of the engine, can prevent the active ingredients thereof from being extracted and emulsified by methanol and is particularly suitable for engines using M85 or M100 methanol gasoline as a fuel.