The invention discloses a preparation method of a medical dressing. Firstly, polyvinyl acetate, methyl vinyl ether-maleic anhydride copolymer and collagen are dissolved in an aqueous ethanol solution to obtain an electrospinning liquid primary material I, and then the polyvinyl acetate Dissolving methacrylic acid, acrylamide and N,N-methylenebisacrylamide with formic acid aqueous solution to obtain the electrospinning solution primary material II, and then mixing the electrospinning solution primary material I with the electrospinning solution primary material II, Adding nano clay, nano silver, vitamin C, borax, ethylene glycol and mannose, emulsifying after stirring, spinning the obtained electrospinning solution into a fiber film by electrospinning, vacuum filtering and drying to obtain a medical dressing. The obtained medical dressing can effectively sterilize and eliminate inflammation, improve the microcirculation of tissues around the injury, play the role of analgesia, inhibit bacterial reproduction and repair wounds, and is safe to use and has no toxic and side effects on human body.