Provided is a beam shaping body for neutron capture therapy, comprising a beam inlet, a target material, a retarder adjacent to the target material, a reflector surrounding the retarder, a thermal neutron absorber adjacent to the retarder, a radiation shield provided inside the beam shaping body and a beam exit, wherein the target material and a proton beam incident from the beam inlet undergo a nuclear reaction to produce neutrons, the neutrons form a neutron beam defining a main axis, and the neutrons produced from the target material are retarded by the retarder to an epithermal neutron energy range； wherein the material of the retarder is made of MgF2 or a mixture containing MgF2 and 6LiF accounting for 0.1-5% in percentage by weight of the MgF2, which is subjected to a powder sintering process using a powder sintering device so as to change a powder or a powder compact into blocks, the reflector guides neutrons deviating from the main axis back to the main axis so as to improve the intensity of the epithermal neutron beam, the thermal neutron absorber is used for absorbing thermal neutrons so as to avoid overdose in superficial normal tissue during a therapy, and the radiation shield is used for shielding leaking neutrons and photons so as to reduce the dose of normal tissues in non-radiation areas.
