The invention belongs to the field of biotechnology, and relates to an allogeneic B cell vaccine against various human-susceptible viruses and a preparation method therefor. The vaccine has anti-tumor and/or anti-viral preventive and/or therapeutic effects. Specifically, the present invention provides a B cell composition, wherein comprising an allogeneic B cell and a virus antigen, the B cell composition is irradiated with a certain dose of ionizing irradiation. The present invention also provides a B cell vaccine, comprising the above B cell composition. The invention also provides a preparation method for the B cell vaccine and a method and system for improving the antigen presentation ability of the B cell.