The invention provides a combined inactivated vaccine for an avian influenza virus and a fowl adenovirus. An H9 subtype avian influenza virus QDY strain and an I-group 4-type aviadenovirus YBAV-4 new strain used by the vaccine are high in TCID50/EID50 valence and good in immunogenicity and can well withstand attacks of the H9 avian virus and various local separate viruses. The vaccine prepared by the invention is good in safety, and free of local and whole-body adverse effects caused by the vaccine. Through analysis of characters, a safety test and efficacy test data in a storage-life test, the combined vaccine is free of an obvious difference from a single vaccine of a similar product in effect, and is stable and effective; the efficacy test result proves that the antibodies of the combined vaccine and two single vaccines are kept at a high level and are faster in antibody generation of similar products; and a control group antibody is negative.