Abstract: Hydrogen energy，as a secondary energy source with zero pollution and high calorific value，has always been a very important subject for efficient production and utilization. At present，the hydrogen production mainly relies on theconversion of fossil fuels，especially from coalcoking and gasification processes. However，the toxic gases are typically generated during the coal coking productionprocess,such as methane and carbon monoxide.The gasification process can also produce large amounts of carbon dioxide. Besides，the hydrogen purity is insufficient for abovetwo conventional methods，which are also harmful for the environment. Therefore，it is very important to finda new method with low carbon emission，high hydrogen production and environmental protection.The proton exchange membrane water electrolyzer(PEMWE),as one of the most promising ways to produce hydrogen by electrolysis of water，it possess a wide range of rapid dynamic response ability. Therefore，PEMWE has a promising application in the dynamic balance of new energy consumption and power grid with high proportion of new energy. However,thequick start/stop，overload,and dramatically variable loadhave serious impacts on the key material and heat/mass transportation process，which are unfavorable for PEMWE performance and life time.It retards the further commercialization of PEMWE technology. Therefore，it needs analysis the attenuation and failure mechanisms of PEMWE system，which can provide important guidance for the development of high-performance，long-life PEM hydrogen production units working on the fluctuating operating conditions.The study mainly discussesthe traditional coal hydrogen production technology and its disadvantages. Continually，the basic principle and characteristics of PEMWE technology is introduced including present development and degradation mechanism for catalytic layer，proton exchange membrane，and polar plate. The corresponding coping strategiesare finally analyzed.