Abstract: 【Objective】For the problem of the diversity of PRRSV strain and the ineffectiveness of vaccine immunization, the best vaccination scheme for porcine reproductive and respiratory syndrome vaccine was explored. 【Method】 The study was carried out in three pig farms (A, B and C) and four different combinations of PRRS vaccines were used in each farm. Group 1: 14-day-old piglets immunized with PRRS attenuated vaccine and inactivated vaccine. Group 2: 14-day-old piglets immunized with PRRS attenuated vaccines and 35-day-old piglets immunized with inactivated vaccine. Group 3:14-day-old and 35-day-old piglets immunized with attenuated vaccines. Group 4: 14-dayold piglets immunized with PRRS attenuated vaccines. The effects of the PRRS vaccine against PRRSV were evaluated through antibody titer, viremia, and production parameters. 【Result】 By comparing different immunization groups, it was found that A2, B3 and C3 had the highest antibody levels and the S/P were 2.50, 2.63 and 2.99, respectively. The positive rates of PRRSV nucleic acid in serum A2, B2, B3 and C1 were the lowest, which were 12.5%, 0, 0, 6.3%, respectively.The incidences of A1, B2 and C1 were the lowest, which were 10%, 2% and 8%, respectively. 【Conclusion】 The combined immunization of 14-day-old PRRS attenuated vaccine and inactivated vaccine, and 14-day-old PRRS attenuated vaccine and 35-day-old inactivated vaccine showed the best immunization effects.