The invention relates to preparation and application of an infectious bursal disease (IBD) protein engineering vaccine. The preparation method comprises the following steps: connecting B cell neutralizing epitope and T cell immunizing epitope of IBDV (infectious bursal disease virus) primary structure proteins VP2 and VP3 as a vaccine frame structure through a flexible linker, connecting with cell factor poultry interleukin 15(chIL-15) in series, cloning into a pRSETB vector, transforming Escherichia coli, fermenting, purifying, emulsifying and the like to obtain the IBD protein engineering vaccine with ideal immunogenicity. The invention also relates to an application method of the vaccine. The animal experiment indicates that the IBD protein engineering vaccine has equivalent effects to the live virus vaccine on the humoral immunity and cellular immunity level, and can stimulate the generation of T lymphopoiesis immunoreaction on the cellular level and the generation of antibody immunoreaction with virus neutralizing activity on the humoral level. The attacking protection test indicates that the IBD protein engineering vaccine group has obviously better effects than the live vaccine group.