The invention discloses a tambusu virus E protein B cell epitope and a coding gene and application thereof. The amino acid sequence of the tambusu virus E protein B cell epitope is shown as SEQ ID NO.1. According to application of the tambusu virus E protein B cell epitope to preparation of tambusu virus vaccines, high-level specific antibodies can be generated in an induced mode in bodies of epitope protein immune ducklings expressed through escherichia coli, and the antibodies can neutralize a tambusu virus and protect the host against being attacked by the virus; the B cell epitope has goodantigenicity, is a non-totivirus antigen, is good in safety and contains no unrelated impure protein; and in addition, the tambusu virus E protein B cell epitope can further construct novel multi-epitope vaccines with other types of epitopes, and thus the B cell epitope has good and wide application prospects.