The invention discloses a chitosan derivative colloidal solution. The solution is composed of 25-35 parts of sodium carboxyamino glucosamine, 15-20 parts of sodium carboxymethylcellulose, 5-10 parts of nicotinamide, 4-8 parts of glycerol, 1-5 parts of mannitol, 2-5 parts of microcrystalline cellulose, 1-3 parts of antioxidant, 5-15 parts of gelatin, 0.5-1 part of glutaraldehyde, 0.2-0.6 part of emulsifier and 60-80 parts of injection water. A preparation method of the solution includes the following steps of S1, adding nicotinamide and sodium carboxymethylcellulose into the injection water, stirring the mixture until the mixture is completely dissolved, adding mannitol, and then obtaining a dissolved solution A; S2, adding sodium carboxyamino glucosamine into the injection water, and conducting heating and stirring for dissolution to obtain a dissolved solution B; S3, mixing the dissolved solution A with the dissolved solution B to obtain a mixed dissolved solution C; S4, adding glycerol, microcrystalline cellulose and the antioxidant into the mixed dissolved solution C, stirring the solution uniformly, and then obtaining the chitosan derivative colloidal solution. The chitosan derivative colloidal solution has the advantages that wounds are effectively cleaned, resistance to bacteria and inflammation is achieved, bleeding is stopped, permeation is prevented, and healing is facilitated.