The neutron capture therapy system provided by the present application includes an accelerator for generating a charged particle beam, a neutron generating portion that reacts with the charged particle beam to generate a neutron beam, and a beam shaping body. The beam shaping body includes a receiving portion, a retarding body, a reflector, a shielding device and a beam outlet, the receiving portion is provided with a vacuum tube connected to the accelerator, and the neutron generating portion is disposed at an end of the vacuum tube, the vacuum tube transmits the charged particles acceleratedby the accelerator to the neutron generating portion to cause the neutron generating portion to react with the charged particle beam to form the neutron beam, the neutron generating portion moves between a first position and a second position, in the first position, the neutron generating portion reacts with the charged particle beam to generate neutrons, in the second position, the neutron generating portion is detached from the beam shaping body, and the beam shaping body and the shielding device keep the neutron generating portion in the shielding through movement from the first position to the second position to prevent that the radiation leaked from the neutron generating portion is exposed to the worker.