Abstract: With the aim of “carbon peaking” and “carbon neutrality” in China, hydrogen energy will play a crucial role of in the future. The third-generation nuclear power (GEN-Ⅲ) features a relatively low reactor outlet temperature, with the primary application of its generated electric energy to direct electrolysis of water to produce hydrogen. In contrast, the fourth-generation nuclear power (GEN-Ⅳ) has higher thermal efficiency and reactor outlet temperature. Considering the matching of reactor outlet temperature with the hydrogen production process, cogeneration can be employed to effectively reduce the cost of hydrogen production. Sodium-cooled fast reactor (SFR) is one of the GEN-Ⅳ reactors, which has the advantage of high reactor outlet temperature, high efficiency and high-tech maturity, and can provide the thermal power and electrical energy for the hydrogen production process. SFR also have advantages of proliferation of nuclear fuel and burn long-lived radioactive nuclides. The closed fuel cycle formed by the development of fast reactors and pressurized water reactors can effectively achieve the sustainable development of nuclear energy. Hydrogen production could be considered in the design of the next generation million kilowatts-level fast reactor (CFR1000), making the hydrogen production process more economical and reduction of carbon emissions, simultaneously. Considering the reactor outlet temperature and the aim of zero-carbon emission during the hydrogen production process, the results reveal that the most suitable hydrogen production methods for SFR are the thermo-chemical cycle (copper-chlorine cycle) and conventional electrolysis. For conventional electrolysis, hydrogen production efficiency is relatively low, but the technology maturity is much higher compared with the other methods. For the thermo-chemical cycle (copper-chlorine cycle), technology maturity is relatively low but has higher hydrogen production efficiency, which could make the hydrogen production process more economical in the future. Based on the hydrogen economic evaluation program HEEP (V2021) which was developed by the IAEA, an economic study on the hydrogen production cost per kilograms of CFR1000 was conducted, which was verified by the fourth-generation reactor economic evaluation software G4-ECONS V3.0 developed by GIF. The cost of the hydrogen production by conventional electrolysis coupled with the CFR1000 is 3.05 /kg, and the cost of hydrogen production process coupled with the thermo-chemical cycle is 4.83 /kg. However, with the investment ratio reduction of SFR, and the potential impact of carbon sinks in the future, the cost of hydrogen production will be further explored. HEEP calculation results show that a decrease in the overnight investment of CFR1000 could significantly reduce the cost of hydrogen production. Overall, SFR shows great promise in the field of hydrogen production in the future.