The invention relates to a method for preparing a gallic acid quinolone drug salt and a preparation method thereof. By adopting the method provided by the invention, a series of gallic acid quinolone drug salts are prepared, such as gallic acid norfloxacin, gallic acid ciprofloxacin, gallic acid ofloxacin, gallic acid levofloxacin, gallic acid prulifloxacin, gallic acid pefloxacin, gallic acid mosifloxacin and the like. The gallic acid quinolone drug salt prepared by the invention has pharmacological action of quinolone and also has the pharmacological action of gallic acid, two different pharmacological action mechanisms can realize synergic antibacterial action, and the gallic acid quinolone drug salt can be prepared into tablets, dispersible tablets and capsules used for oral administration and injection used for injection and also can be prepared into suppository and lotion which are used for local application (rectum application and vagina application). The quinolone drug is a broad spectrum antibiotic, and the gallic acid has antibacterial, antiviral and antitumour functions. The preparation method of the quinolone drug salt can mutually enhance antibacterial action after being applied.