Hydrogen isotope separating device and method

The present invention provides a kind of hydrogen isotope separating apparatus and method. The hydrogen isotope separating apparatus includes several separating stages, gas transferring pump, gas flow controller, gas flow control valve, etc. cascaded in certain mode, and each of the separating stages includes several parallel separators. After mixed material gas of protium, deuterium and tritium is injected in the middle part of the separating chain, and through the superposed successive separations, deuterium and tritium gas product with very low protium content may be taken out from one end of cascade chain while taking out protium and deuterium tail gas with very low tritium content. The present invention is suitable for continuous separation of great amount of hydrogen isotopes in different fields.