The Helium blanketing effect on LaNi5-xAlx and ZrCo alloy is researched. Hydrogen absorption and desorption change due to gaseous helium has been investigated by the serial experiments under different conditions. Helium reduces hydrogen absorption and desorption rate, but it would not change the ultimate quantities of hydrogen absorption and desorption. The surface electron spectrum of LaNi5-xAlx was examined by a multi-functional spectrometer. The examination shows that inert gas would not affect the electron state of the alloy surface and also the decomposition and absorption course of hydrogen molecule on the alloy surface. The research shows that Helium blanketing course is divided into two stages of "bulk flow" and "diffusion flow". After reaching the blanketing pressure the microcosmic course is molecule migration controlled by diffusion.