The present disclosure provides a neutron capture therapy system, including a beam shaping assembly for shaping the neutron beam. The beam shaping assembly includes a moderator and a reflecting assembly surrounding the moderator. The neutron generator generates the neutrons after irradiation by the charged particle beam. The moderator moderates the neutrons generated by the neutron generator to a preset energy spectrum. The reflecting assembly includes a reflecting assembly to deflected neutrons back to the neutron beam and a supporting member to support the reflectors. A lead-antimony alloy is for the reflecting assembly to mitigate a creep effect that occurs when only a lead material is for the reflectors, thereby improving the structural strength of a beam shaping assembly.
