The invention belongs to the technical field of vaccine production, and particularly discloses a production method of a haemophilus parasuis/mycoplasma hyopneumoniae bivalent inactivated vaccine. Themethod includes: performing fermenting culture of mycoplasma hyopneumoniae in a bioreactor; performing fermenting culture of serum IV type haemophilus parasuis and serum V type haemophilus parasuis ina fermentation tank; inactivating, concentrating and purifying the microbial liquids after the fermenting cultivation, mixing the microbial liquids according to certain ratio, and adding an immuno-enhancer and a vaccine adjuvant to obtain the haemophilus parasuis/mycoplasma hyopneumoniae bivalent inactivated vaccine. The vaccine composition has excellent specificity and good immunity, can achievethe object of prevention from the two diseases by one injection, is more economical and practicability, can avoid repeated inoculation and reduces vaccine cost and manpower cost. The bivalent inactivated vaccine is very suitable for prevention and treatment on breeding farms with mixed infection of the diseases.