The invention discloses a preparation method of a natural pet flavoring agent. The preparation method comprises the following steps of: firstly, preparation of meat enzymolysis liquids: a beef enzymolysis liquid, a chicken enzymolysis liquid, a pork enzymolysis liquid, a fish enzymolysis liquid and a shrimp meat enzymolysis liquid; secondly, sequentially adding the beef enzymolysis liquid, the chicken enzymolysis liquid, the pork enzymolysis liquid, the fish enzymolysis liquid, the shrimp meat enzymolysis liquid, reducing sugar, amino acid, L-cysteine monohydrochloride, yeast extract, thiamin, spice and grease into a reaction kettle, fully mixing, evenly blending, heating to 90-125 DEG C for thermal reaction for 1-2 hours, cooling to 40-55 DEG C after the reaction is completed, and filtering through a 40-50-mesh sieve to obtain the natural pet flavoring agent. The preparation method of the natural pet flavoring agent provided by the invention adopts the beef enzymolysis liquid, the chicken enzymolysis liquid, the pork enzymolysis liquid, the fish enzymolysis liquid and the shrimp meat enzymolysis liquid for simultaneous Maillard reaction, and the obtained natural pet flavoring agent is natural in flavor, mellow in taste and meaty, improves the palatability of pet foods, and increases the interest of pets in foods and the food intake of the pets.