Abstract: The hydrogen permeation rate and separation performance of hydrogen and helium by PdY purifier and traditional purifier were studied. The results show that the hydrogen permeation rate of PdY purifier increases as the differential pressure increases. When the differential pressure is in the range of 0.004-0.04 MPa, the hydrogen permeation rate of PdY purifier is approximately 3 times of traditional purifier. The time of separating hydrogen and helium is significantly shortened using PdY purifier. After long cycle of separation, the three components of hydrogen and helium gas mixture are well separated; the hydrogen content of helium is reduced to 0.03%.