The invention discloses a natural rubber liquid slurry containing chitosan / sericin and a preparation method thereof, and belongs to the field of high polymer chemistry. The invention is characterized in that the preparation method comprises the following steps: respectively preparing a chitosan water solution and a sericin water solution, mixing the two solution, and regulating the pH value of the mixture to 9-11 by using ammonia water and a citric acid solution; and adding the obtained chitosan / sericin mixed solution to a natural latex slurry, adding a laurate surfactant, and mechanically stirring the mixture uniformly to obtain the natural rubber liquid slurry containing chitosan / sericin. The invention has the advantages that the chitosan has the functions of adsorbing water soluble proteins in the latex, inhibiting bacteria and viruses from breeding, and the like; and the sericin has the functions of oxidation resistance, allergy resistance, hydrophilia, oil resistance and the like, thereby enhancing the emulsion phase stability and the preservation effect of the natural latex. In particular, the product obtained by using the method overcomes the defects of short service life, easy aging and sticking, poor oil resistance, initiation of protein allergy and the like in the traditional natural latex product.