Abstract: An alkali metal reactor power supply, including: a reactor vessel, the bottom part of which is provided with a liquid alkali metal; a reactor core, which is arranged in the reactor vessel and includes a plurality of fuel rods and a radial reflection layer arranged at the periphery of the plurality of fuel rods, wherein the surface of each fuel rod is provided with a first liquid absorption core, the bottom part of the reactor core is provided with second liquid absorption cores which are connected to the first liquid absorption cores, and the second liquid absorption cores can be in contact with the liquid alkali metal; and alkali metal thermoelectric converters, which are arranged along the circumferential direction of the radial reflection layer, and divide the inside of the reactor vessel into a high-pressure steam chamber located above the alkali metal thermoelectric converters and a low-pressure steam chamber located below the alkali metal thermoelectric converters.