The invention discloses a preparation method of an animal specimen. The method comprises the following steps: (1) treating a specimen material: selecting an animal dying naturally as the specimen material, stuffing cotton in the nares, oral cavity and anus of the animal, carrying out cryopreservation after ventilation cooling, and after 6-7 hours, taking the animal out and naturally unfreezing the animal; (2) carrying out taxidermy which comprises chest taxidermy, leg taxidermy, tail taxidermy, back wing taxidermy, neck and sole taxidermy and head taxidermy; (3) preparing the taxidermal animal into a model: sculpturing a cystosepiment into a 1: 1 prosthesis flesh model, supporting the wing skeleton, tail and two legs with lead wires, smearing antisepic medicine on the inner side of the hide, fixing lead wires on the head skeleton to tie up the neck, and fixing the lead wires on the neck and the lead wires on the wings and the legs on the prosthesis; (4) dressing the model: restoring the original ecological appearance, and placing the dressed model at a shady, cool and ventilated place. The preparation method is simple and easy to operate, capable of maintaining the original ecological appearance of the animal specimen, high in specimen quality, free of peculiar smell, and prolongs the service life of the specimen material.