Preparation method of biological dressing containing nano silver, zinc and bismuth

The invention discloses a preparation method of a biological dressing containing nano silver, zinc and bismuth, which comprises the steps of: synthesizing chitosan and/or a nano silver, zinc and bismuth compound as a chitosan derivative by using a solid phase synthesis method; dissolving into a solution; adding a proper quantity of glycerol, collagen and the like; and obtaining a film dressing by adopting a curtain coating film-forming method or obtaining a sponge dressing by using a freezing drying method. The biological dressing has the functions and the advantages of nano silver, zinc and bismuth, and chitosan or chitosan derivative, and has the characteristics of better contact bacteriostasis, wide antimicrobial spectrum, durable action time, wound repairmen, ulcer curing and the like.