In order to provide a neutron therapy apparatus which give multi angles neutron beam irradiation, the neutron therapy apparatus includes: a beam shaping assembly including a moderator and a reflector surrounding the moderator, wherein the moderator moderates neutrons to a predetermined energy spectrum and the reflector guides deflected neutrons back to enhance the neutron intensity in the predetermined energy spectrum; a neutron generator embedded inside the beam shaping assembly, wherein the neutron generator generates neutrons after irradiated by an ion beam; at least a tube for transmitting the ion beam to the neutron generator, wherein the tube defines at least an axis; deflection magnets for changing the transmission direction of the ion beam; a collimator for concentrating neutrons; and an irradiation room for receiving a irradiated object, wherein the beam shaping assembly rotates around the axis of the tube.