The invention belongs to the technical field of biological products for animals and particularly relates to a vaccine composition and a preparation method thereof. The vaccine composition comprises avian influenza virus H9 subtype antigens, aviadenovirus 4-type antigens, avian reovirus 2-type virus antigens, avian leukosis J-type antigens and an adjuvant. The vaccine composition has good immune effect for the avian influenza virus H9 subtype antigens, the aviadenovirus 4-type antigens, the avian reovirus 2-type virus antigens and the avian leukosis J-type antigens.