The 20kW PEM pure water electrolysis hydrogen production system adopts a modular design, which solves the safety, efficiency and reliability problems of the hydrogen production system. The system has high integration, accurate control, fast response speed, strong overload ability, low energy consumption, high hydrogen production efficiency, and high product purity, and can provide strong support for the commercial application of green hydrogen equipment. The product is in good running condition, the stable operating load range of the system is 3%-150%, the maximum overload capacity can reach more than 150%, the maximum hydrogen production pressure reaches 3.8MPa, and the product hydrogen purity is>99.999%. It also has remote control, intelligent supervision, data cloud upload and other functions.