The invention relates to a gasoline additive, which is composed of, by weight part, 5-90 of tensile ring cage type hydrocarbon, 3-95 of a detergent dispersant, and 0-80 of an assistant. The tensile ring cage type hydrocarbon is pentacyclic[5.4.0.0<2.6>.0<3.10>.0<5.9>]undecane or its alkyl substituendum, and dimer derivative. The detergent dispersant is polyisobutene amine, polyether amine, amide type polymer or other amine ashless detergents. The assistant is one of or a mixture of several of an antioxidant, a metal passivator, and a solvent. The gasoline additive provided by the invention has a simple production process, and by adding 0.5-5 per thousand (weight percentage) of the additive into gasoline, gasoline can be saved by 2-25%, and the use effect is good.