Abstract: It compares two means of hydrogen purification in hydro liquification production,and manufactures 77K purification device of high pressure hydrogen。After high pressure hydrogen purified under liquid nitrogen temperature,it comes into hydrogen liquefier and beliquefied circulate.This reduces harmful influence in production and ensures hydrogen purity.So it simplifies production technology and energy resources can be made a full use.It also gives device methods of absorber、choices of absorbent and simple and practical conclusion.