Abstract: The nuclear reactor power is one of the most important power supply options for the lunar research station. To meet the electricity demand of the lunar research station, a single-cell thermionic lunar power reactor core scheme with a net power of 40kWe and a lifetime of 10 years was presented. As the single-cell thermionic fuel element’s fuel loading can be completed either on the earth or relatively conveniently on the lunar surface, two core schemes were given respectively. The radial power distribution of the reactor core was optimized by fuel partition loading, and the power distribution, temperature effect, worth of bowl and safety rod, burnup and hydrogen leakage effect, reactivity balance and special critical safety problem of the core were calculated and analyzed. The results show that both of the core schemes can meet the requirements of neutronics and special critical safety, and have their own characteristics. This research results can provide reference for the selection of lunar power reactor core scheme and the formulation of workflow.