The invention discloses a preparation method of a high-titer egg yolk immunoglobulin for a porcine reproductive and respiratory syndrome (PRRS), and belongs to the technical field of antibody preparation. The preparation method of the high-titer egg yolk immunoglobulin for the porcine reproductive and respiratory syndrome, which is disclosed by the invention, comprises the following steps: immunizing laying hens with current existing live vaccines for the porcine reproductive and respiratory syndrome of immunized pigs, and feeding the laying hens with extracts of folium mori and eucommia ulmoides during immunization; collecting eggs immunized by PRRS vaccines for 2-6 weeks, extracting egg yolk water extract liquid from the collected eggs, and purifying the egg yolk water extract liquid by a freezing and thawing method so as to obtain the egg yolk immunoglobulin IgY. According to the preparation method disclosed by the invention, the extracts of folium mori and eucommia ulmoides are supplied in a feeding method, so that the immune functions of bodies can be obviously improved, the immunoglobulin generation is promoted, and the preparation method conforms to the current demands of green food; on the study of the preparation method disclosed by the invention, the extracts of folium mori and eucommia ulmoides are selected to be used as an immunoenhancer to prepare the high-titer egg yolk immunoglobulin for the porcine reproductive and respiratory syndrome, and a practical value on urgently treating the porcine reproductive and respiratory syndrome is achieved, so that the important significance on reducing the economic loss of the pig industry and promoting the development of novel biological medicine for animals is achieved.