The design characteristics of ACP100 make the radiation steaming become one of the radiation protection problems that need to be paid attention to,and it is necessary to carry out targeted shielding design.In order to improve the accuracy of discrete ordinates method in small modular reactor modeling calculation,a visual modeling plug-in of discrete ordinate method based on the code NX is developed in this study,which can directly define all attributes in NX graphical interface,and automatically complete meshing to form a complete calculation input.In this study,the radiation streaming calculation of ACP100 is completed based on the visual modeling technology and the self-developed three-dimensional discrete ordinates transport calculation code Hydra,and a special shielding module is set for the radiation streaming problem,which greatly reduce the thermal neutron flux in the main pump room and the radiation dose of the operating platform.