The invention provides a polyvalent inactivity vaccine for preventing and treating atrophic rhinitis of a swine and a preparation method thereof. The polyvalent inactivity vaccine contains inactivated Bordetella bronchiseptica, Pasteurella multocida A, Pasteurella multocida D and PMT (Pasteurella Multocida Toxin) anatoxin. The invention further provides a novel method for culturing and extractingPMT. Compared with the traditional atrophic rhinitis of the swine, the polyvalent inactivity vaccine for the atrophic rhinitis of the swine, provided by the invention, can be used for more generally and effectively treating and preventing the atrophic rhinitis of the swine by comprehensive antigen protection. Finally, in the polyvalent vaccine provided by the invention, the vaccine with a plurality of antigens in a reasonable proportion can be used for solving the problem that the plurality of the antigens interfere each other, thereby improving an immune effect. Furthermore, the inventor provides a water adjuvant by which defects such as incomplete absorption, large side reaction and the like after the traditional alumina gel adjuvant, Freund adjuvant and water-in-oil adjuvant are injected into the water adjuvant can be overcome.