The invention discloses a method for preparing peptone by using chicken slaughtering by-products. The method comprises the steps of 1, pretreating raw materials; 2, carrying out protease hydrolysis; 3, carrying out enzyme deactivation, decoloration and deodorization; 4, neutralizing and filtering; 5, concentrating, drying and crushing. The method has the beneficial effects that the bone oil produced in the processing process can be used for preparing oleic acid, stearic acid, soaps, glycerol, high class lubricating oil and household chemicals, and bone grains and bone powder are mainly used as main raw materials of feed, compound fertilizers and the like. The method is massively applied to the fields of fermentation in biological pharmacy, edible fungus cultivation and the like, so that the demands of development of feed industry as well as deep processing and fine processing of chemical products can be met; the demand for the peptone produced by animal by-products is increased year by year, so that the method has wide market application prospects.