Abstract: A combined application of Haemophilus parasuis (HPS) LC strain having a deposit number of CGMCC No. 5257 and HPS LZ-20100109 strain having a deposit number of CGMCC No. 5802 in preparing a bivalent inactivated vaccine is provided, relating to HPS disease vaccines in a field of veterinary biologics. The combined application of the HPS LC strain and the HPS LZ-20100109 strain in preparing the bivalent inactivated vaccine is safe and reliable, providing not only a homologous challenge protection against serotype 1 and serotype 5, but also certain cross protection against heterologous challenges of serotype 2, serotype 4, serotype 10, serotype 12, serotype 13, serotype 14, and serotype 15 of HPS. The combined application of the HPS LC strain and the HPS LZ-20100109 strain has an obviously increased effect. After immunizing swine, a relatively strong immunity is generated; an incidence rate and a mortality rate of inoculated swine decrease obviously.