The invention discloses a method of improving antibacterial performance of nanosilver. The method improves the antibacterial performance of nanosilver in a water environment by adopting a monovalent electrolyte. The monovalent electrolyte is an electrolyte containing monovalent cations. By means of synergistic interaction on microbial toxic action of nanosilver by adopting the monovalent cations,the antibacterial performance of nanosilver can be improved effectively. The method has the advantages of simple and feasible operation, low cost, high practicality, wide application range and the like. A used reagent is environment-friendly and is easy to obtain. The antibacterial performance of nanosilver in plants, animals, microorganisms and human bodies can be improved, the nanosilver is goodin antibacterial effect and the method has very good application value and application prospect.