Electrolytic water technology can be combined with renewable energy to produce zero-emission and zero-pollution green hydrogen on a large scale，so as to realize the consumption and storage of renewable energy. At the same time，the purity of hydrogen produced by electrolysis can reach 99.9%. This report analyzes the hydroelectrolysis of alkaline liquid electrolysis cell to produce hydrogen，the hydroelectrolysis of proton exchange membrane to produce hydrogen and some new electrolysis water technologies，and introduces the representative demonstration of renewable energy electrolysis water projects. It is concluded that hydrogen energy will become an important part of China’s energy system，so the development of hydrogen industry is a strategic choice to optimize the energy structure and ensure national energy security. In the future，under the power structure dominated by renewable energy，the emission intensity of electrolytic water to produce hydrogen will be significantly reduced，and it will have more synergic capability with fluctuating renewable energy power. It plays an important role in realizing China’s “energy independence” strategy and has great potential for development.