The invention relates to a production method of alkylation gasoline. According to the method, an adamantyl ion liquid modified strong acid is used as a catalyst, and low-carbon olefin and isobutane or isopentane are catalyzed to be subjected to direct addition, so as to generate highly branched isoparaffin. Cations of adamantyl ion liquid have a structure shown as the description, wherein R1, R2, R3, R4, R5 an R6 are the same or different C1 to C30 alkyl, and n is an integer from 0 to 8; anions of the adamantyl ion liquid comprise at least one of HSO4<->, CF3SO3<->, NTf<2->, H2PO4<->, PW12O40<3->, p-CH3-(C6H4)SO3<->, PMo12O40<3->, H2PW12O40<->, PF6<->, SBF6<-> and [B(HSO4)4]<->. According to the method for alkylating with the assistant catalysis of the adamantyl ion liquid, provided by the invention, the service life of the catalyst can be remarkably prolonged, and the selectivity and yield of a target product (trimethylpentane) are improved. The method has simple conditions and is simple and easy to operate, and industrialized popularization and application are facilitated.