Nowadays, energy demand increases gradually. However, based on the clean and sustainable energy requirement, the hydrogen is the most potential energy in the 21 centuries. The copper-chlorine thermochemical cycle is a low-energy consumption process. The electricity requirement of pure water electrolysis process can be replaced by a large amount of solar power or waste heat from the nuclear plant in the copper-chlorine thermochemical cycle. The electricity requirement of the thermochemical cycle only takes half of the electricity requirement of pure water electrolysis process. Under the well-heat recovery, when reaction steps of the thermochemical cycle are fewer, the energy efficiency of the hydrogen production will be higher. On the other hand, when talking about the heat recovery, the thermochemical cycle reaction steps are more, the energy efficiency of the hydrogen production will be higher.