H9N2 subtype bird flu cold adaption attenuated strain and application thereof

The invention discloses a H9N2 subtype bird flu cold adaption attenuated strain and application thereof. The H9N2 subtype bird flu cold adaption attenuated strain H9AIV-SD/01/10-CA has a preservation number: CGMCC NO. 10908. The H9AIV-SD/01/10-CA strain is attenuated strain, can serve as a live vaccine and has the following advantages compared with current inactivated vaccine: (1) cell-mediated immunity and mucosal immunity with a crossing protection effect can be generated to resist infection of different epidemic strains; (2) cellular immune response can be induced to fast generate a protection effect after immune, and can resist infection of influenza virus in 10-14 days after immune; (3) the inoculation times are less, immune duration is long and the strain is very critical to prevention of H9N2 virus.