The invention relates to a method for preparing isoparaffin-rich gasoline by dimethyl ether catalytic conversion. According to the method, raw material gas containing dimethyl ether is converted by ametal nanocluster modified mesoporous molecular sieve catalyst under certain conditions to produce the isoparaffin-rich gasoline. The gasoline fraction hydrocarbons (hydrocarbons with carbon atom number of 5-11) produced by the method have more isoparaffin, and can meet the content requirements of the world clean fuel standards for aromatics and olefins, meanwhile, the isoparaffin-rich gasoline can be continuously and stably produced by the method, a novel technical route is provided for the production of high quality gasoline from non-petroleum resources, and great market prospects are achieved.