Abstract: Shielding calculation is one of important parts of nuclear reactor design. Its calculation results directly affect the lifetime of nuclear power plant and radiation safety of surrounding environment. JSNT is a three-dimensional massively paralleled discrete ordinate neutron/photon transport code, which is developed by CAEP Software Center for High Performance Numerical Simulation. Region decomposition is used to realize large-scale parallel computation, so JSNT has high simulation accuracy and computational efficiency. Based on geometry modeling of BHR-2, JSNT was used to carry out the shielding calculation and analysis. Three-dimensional neutron flux density distribution and specific radioactivity were calculated at the location of surveillance capsule and neutron dosimeter. The smaller the mesh, the better the agreement between the calculated results and the experimental values. Except for the ²³⁷Np(n,f)-¹³⁷Cs and ²³⁸U(n,f)-¹³⁷Cs at the location of neutron dosimeter, the relative deviation of calculated numerical results and experimental values is less than 20%, which meets the engineering requirements.