A neutron capture therapy system, comprising a beam shaping body (10), which comprises a beam inlet (11), a neutron generator (12) provided in the beam shaping body (10), a moderator (13) adjacent to the neutron generator (12), a reflector body (14) surrounding the moderator (13) and a beam outlet (15) the neutron generator (12) and a proton beam emitted from the beam inlet (11) generate neutrons by means of a nuclear reaction, the moderator (13) slows the neutrons generated by the neutron generator (12), and the reflector body (14) guides diverging neutrons back toward the moderator (13) to increase epithermal neutron beam intensity the beam shaping body (10) comprises at least one movable member (16) capable of moving in the direction away from or toward the neutron generator (12), said movable member (16) having a first position (L1) and a second position (L2), and said movable member (16) being capable of moving between the first position (L1) and the second position (L2) when the movable member (16) is in the first position (L1), the neutron generator (12) can be replaced, when the movable member (16) is in the second position (L2), the neutron generator (12) cannot be replaced. In the present system, the neutron generator can be easily replaced, the structure is simple, and operation is flexible.
