Abstract: The characteristics of the CAP1400 cavity shielding design are introduced,and the methods,process and the concerns for neutron shielding design near the RPV are analyzed.Based on the Monte Carlo software,the fine model for the CAP1400 containment building is built,and the advanced method of variance reduction techniques are used for design.The radiation distribution of the containment building before and after the neutron shielding modules setting are compared and analyzed.The necessity of neutron shielding is demonstrated,and the optimization design of the neutron shielding for the CAP1400 nuclear power plant is finally realized.