The invention discloses an alpha-gal epitope modified kit and application thereof. The kit comprises a MES (2-(N-morpholine)ethanesulfonic acid) solution, a UDP-gal (uridine diphosphate galactose) solution, an alpha1,3-GT (galactosyl transferase) solution, a NA (neuraminidase) solution, a FITC-Lectin (fluorescein-lableled antiagglutinin antibody) solution and normal saline. The kit can label tumor cell surface antigen with alpha-gal in vitro, apply labeled tumor cells to in-vitro culture of peripheral blood mononuclear cells or in-vivo injection and present tumor-specific antigen to a human immune system via human antigen-presenting cells so as to improve the ability of the immune system in recognition of tumor cells; reaction is simple and convenient; high efficiency is realized; the system is definite; detection is convenient; and tumor cells can be labeled for preparation of an alpha-gal vaccine. The alpha-gal vaccine is applicable to inoperable patients with tumors or postoperative therapy for killing of residual tumor cells in the bodies of the patients, and also applicable to tumor prevention for tumor-susceptible people, or relatives of patients with tumors or healthy people.