The invention discloses a polymer antibacterial coating and a preparation method thereof. With Fe-MOF nanomaterial, glycerol, Tween 80, p-hydroxybenzoic acid ethyl ester sodium, polyvinyl alcohol andchitosan serving as main raw materials, a layer of sodium alginate nanoscale Fe/MOF antibacterial coating solution and a layer of polyvinyl alcohol-chitosan nanoscale coating solution are combined toform a complete, smooth organic polymer liquid state film, and the liquid state film can inhibit protein, bacteria, human cells and the like from being stuck on the surface of a peripheral venous catheter and biological membranes from forming. The antibacterial coating prepared by the preparation method has better antibacterial property, moreover, the stability of the coating is excellent, and theinvention has a good application prospect.