Abstract: The weight of the radiation shielding seriously is with great effects on the maneuverability of the ship. It is important to improve the maneuverability of the ship by optimization of radiation shielding in a fixed shielding space and reducing the weight of the shielding. In this paper, the optimization methods of radiation shielding in a fixed space is studied based on SuperMC intelligent nuclear design module, and the shielding optimization design is carried out by using Savannah reactor to demonstrate the effectiveness of the method. The results show that the shielding weight of the optimized scheme is greatly reduced compared with the original design scheme, which proves that this approach provides a new technical means for guiding the material selection and shielding layout of ship reactor radiation shielding.