Abstract: To analyze the feasibility of the start-up with non-nuclear steam of sodium-cooled fast reactor turbine under a certain boundary condition, based on the simplified model of the thermal system of the sodium-cooled fast reactor, a thermal balance calculation was established for the start-up with non-nuclear steam, and corresponding optimized schemes were proposed. Results show that, with only using steam generated by the heat storage of the primary and secondary loop of the reactor, the steam flow can not meet the requirements of the start-up with non-nuclear steam, while the start-up with non-nuclear steam of sodium-cooled fast reactor turbine is feasible when combined with auxiliary steam.