Present designs for molten salt thermal reactors require complex online processing systems,which are technologically challenging,while an accelerator-driven subcritical molten salt system can operate without an online processing system,simplifying the design.Previous designs of accelerator-driven subcritical systems usually required very high-power proton accelerators (>10 MW).In this research,a proton accelerator is used to drive a thorium-based molten salt fast energy amplifier (TMSFEA) that improves the neutron efficiency of the system.The research results show that TMSFEA can achieve a longterm stable state for more than 30 years with a rated power of 300 MW and a stabilizing effective multiplication factor (keff) without any online processing.In this study,a physical design of an integrated molten salt energy amplifier with an initial energy gain of 117 was accomplished.According to the bu-up calculation,a molten salt energy amplifier with the rated power of 300 MWth should be able to operate continuously for nearly 40 years using a 1 GeV proton beam below 4 mA during the lifetime.By the end of the life cycle,the energy gain can still reach 76,and 233U contributes 70.9％ of the total fission rate,which indicates the efficient utilization of the thorium fuel.