Antibiotic resistance has become one of the greatest health threats in the world. In this study, a charge-dispersed dimerization strategy is described for the antimicrobial peptide (AMP) mimics via a tunable cationic charge to improve the selectivity between prokaryotic microbes and eukaryotic cells. This strategy is demonstrated with a series of charge-dispersed AMP mimics based on <i>N</i>-arylimidazolium skeletons. These <i>N</i>-arylimidazolium AMP mimics show potent antibacterial activity against strains along with a low rate of drug resistance, good hemocompatibility, and low cytotoxicity. In addition to the elimination of planktonic bacteria, <i>N</i>-arylimidazolium AMP mimics can also inhibit biofilm formation and destroy the established biofilm. More importantly, methicillin-resistant <i>Staphylococcus aureus</i> (MRSA)-induced lung-infected mice can be effectively treated by the intravenous administration of <i>N</i>-arylimidazolium AMP mimic, which enable the design of <i>N</i>-arylimidazolium AMP mimics to offer an alternative avenue to eradicate drug-resistant bacterial infection.