In this study, a new passive residual heat extraction system for single-shell reactor is introduced. Heat pipes (HP) and ribs are installed on the containment dome to improve the heat transfer coefficient of the dome. Airpak software was used for numerical simulation. The conditions of the dome without heat pipes and with heat pipes without penetrating the steel lining were simulated. The results show that under accident conditions, the heat transfer per unit area of the dome is 150 W without a heat pipe, and 1700 W with a heat pipe, which is 11 times higher than the former and consistent with the theoretical calculation results. Under simulated operating conditions, the heat pipe can dissipate about 90% of the heat from the dome, which indicates the effectiveness of the heat pipe thermal conductivity device and provides reference for engineering application. By building a simplified experimental platform, the average temperature differences between the inside and outside of the containment were 22.6 °C, 36.47 °C, and 54.67 °C with heating powers of 400 W, 800 W, and 1200 W, respectively under the condition of heat pipe penetrating the dome steel lining. And a proportional model of the prototype was built for simulation. The results indicate that the experimental data matched well with the simulation results, verifying the correctness of the simulation model.