The invention provides a lead-free synthetic fuel for cars. The lead-free synthetic fuel for cars comprises, by weight, 40 to 60 parts of ethanol, 10 to 30 parts of fatty alcohol polyoxypropylene ether, 6.5 to 17 parts of butane, 1 to 5 parts of ammonia fatty acid salt, 0.2 to 1 part of barium sulfonate, 0.8 to 1.5 parts of a stabilizer, 2 to 3 parts of t-butylperoxy acetate, 5 to 7 parts of oleicacid, 5 to 7 parts of MTBE, 3 to 6 parts of paraffin wax, 0.2 to 1 part of phosphate, 0.2 to 1 part of butane sulfide, 1.2 to 2 parts of methyl silicone oil, 1 to 5 parts of sodium phosphate, 1 partof ethylene glycol, 0.5 to 0.9 part of hydrogen peroxide, 0.5 to 0.9 part by weight of 2,6-di-t-butyl-p-cresol and 1.2 to 2 parts of a composite additive. A temperature for preparation of the lead-free synthetic fuel is in a range of +20 DEG C to -20 DEG C.