Abstract: In order to prepare inactivated porcine Japanese encephalitis virus（A6 strain） and study its immunoprotective effects, in the experiment, porcine Japanese encephalitis virus（A6 strain） was cultured and proliferated on Vero cells, inactivated with β-propiolactone, and the qualified antigen was emulsified with 206 vaccine adjuvant to prepare an inactivated porcine Japanese encephalitis virus vaccine（A6 strain）. The prepared porcine Japanese encephalitis virus inactivated vaccine（A6 strain） was diluted with PBS to 3 dilutions of 1∶5, 1∶50, and 1∶500 to immunize mice and then the challenge was carried out. The gilts were intramuscularly injected with porcine Japanese encephalitis virus inactivated vaccine（A6 strain） and boosted once at an interval of 14 days, and the neutralizing antibody titers of the immunized gilts and piglets were determined. At the same time, the challenge test after immunization was carried out on the reserve sows, which were divided into vaccine immunization group and challenge control group. The sows were challenged with porcine Japanese encephalitis virus（A6 strain） after 30 d of gestation, and the clinical symptoms and health status of piglets delivered were recorded in each group after the attack, and the sick piglets were examined by autopsy to observe the lesions.The results showed that the 1∶50-fold dilution of porcine Japanese encephalitis virus inactivated vaccine（A6 strain） was used to immunize mice and then the challenge was carried out; and the protection rate could reach 80%. The gilts were immunized twice at an interval of 14 days to produce high levels of neutralizing antibodies, and the neutralizing antibody titers of the born piglets could be maintained to 30 days of age. The sows were challenged on the 30 th day of gestation, and all the gestating saws in the vaccine immunized group had normal litter, and all the piglets were alive and all of them were protected. On autopsy of the fetus with onset, case changes such as hydrocephalus, subcutaneous edema, pleural and abdominal effusions, and lymph node congestion were seen.The pregnant sows in the challenge control group suffered from miscarriage, stillbirths, mummies and weak fetuses, and all of them were affected. The results suggested that the porcine Japanese encephalitis virus inactivated vaccine（A6 strain） had good immunoprotective effects.