Objectives The immunization status of Japanese encephalitis in pigs from a large-scale farm in Yuping County, Guizhou Province was investigated to provide reference for the prevention and control of Japanese encephalitis in large-scale farms. Methods 3 960 serum samples were randomly collected from pig herds that had been screened for wild-type Japanese encephalitis infection and vaccinated with the Japanese encephalitis vaccine from 2020 to 2022. ELISA antibody detection kits were used to detect Japanese encephalitis antibody. Results The average immunization qualification rate for Japanese encephalitis at the farm from 2020 to 2022 was 97.20%, 98.33%, and 98.56%, respectively, with an overall immunization qualification rate of 98.03%. The level of antibody was relatively low in the first quarter, with an average immunization qualification rate of 96.36%. The level of antibody was the highest in the third quarter, at 99.60%. The level of antibody in boars and lactating sows was relatively high, with immunization qualification rate of 98.89% and 98.26%, respectively. Pregnant sows had the lowest immunization qualification rate, at 97.73%. Conclusions The overall immune level of Japanese encephalitis in this pig farm was good, but there were certain differences in time and herd. It is necessary to strengthen the management of feeding and the monitoring of immunization.