Abstract: The research aimed to prepare the highly-immunized yolk antibody of porcine reproductive and respiratory syndrome（PRRS） and study its treatment effect. Laying hens were immunized with NVDC-JXA1 strain of inactivated vaccine of highly pathogenic PRRS virus and highly-immunized eggs were collected. The highly-immunized yolk antibody of PRRS was prepared by water dilution and extraction method and aseptic examination, security detection, effectiveness detection and animal protection test were conducted. And it was applied in the clinic practice to observe the treatment effect. The results showed that the agar diffusion titer of the highly-immunized yolk antibody of PRRS prepared by this method reached 1：32, the protection rate reached 100% and the cure rate in the clinic test was 84.5%. The research indicated that the preparation of specific yolk antibody of PRRS was simple and cheap and it could be used in the clinic treatment of PRRS.