An antibacterial dressing for promoting scarless wound healing and a method for preparing the same provided. The dressing consists of 0.05-0.1 part by weight of hyperbranched polylysine anti-scar compound, 0.1-2.0 parts by weight of carbomer, 1-10 parts by weight of a thickener, 2-12 parts by weight of a humectant, 60-90 parts by weight of water and 1-15 parts by weight of a plant extract. The hyperbranched polylysine and the anti-scar drug are grafted and synthesized into a new compound, so that the antibacterial activity of the hyperbranched polylysine and the ability of the anti-scar drug to inhibit the scar formation of the wound are retained; meanwhile, a film with good air permeability and moisture retention can be formed on the skin surface through the film forming agent, so that the wound surface is kept in a moist environment, which is beneficial to wound healing and does not generate scars.