The invention discloses an alcohol-based liquid fuel and a method for preparing the alcohol-based liquid fuel additive. The raw material components of the alcohol-based liquid fuel additive include: 0.4-0.6 parts of dipentyl iron, 0.4-0.6 parts of light aromatics, tertiary methyl 0.4-0.6 parts of butyl ether, 0.4-0.6 parts of tert-butyldimethylsilane, 0.2-0.5 parts of dimethyl silicone oil, 0.9-1.1 parts of octane regulator, 0.9-1.1 parts of isomerization regulator; alcohol The raw material components of the base liquid fuel are: 65-75 parts of alcohol, 25-34 parts of crude benzene, and 0.9-1.1 parts of alcohol-based liquid fuel additive. The preparation method of the alcohol-based liquid fuel is simple, less investment, low cost, no corrosion, no swelling reaction, no modification of the engine, high heat value, good combustion performance, high power, long storage period, high safety and availability Water fire extinguishing, speed up quickly, the exhaust gas is odorless, can effectively reduce the emission of harmful gases, has important strategic significance for ensuring national energy security, has broad application prospects, and has good economic, social and ecological benefits.