Based on the early stage of the palladium interact with hydrogen isotopes of basic research and related technical research, a kind of new method was proposed which can quickly remove a small amount of protium from the deuterium-tritium gas-palladium retention method. The method makes full use of the isotope effect of palladium-hydride system. When hydrogen isotopes gas with a small amount of protium flows through the separation column at normal temperature or low temperature, a small amount of protium priority can be detention in palladium separation material, so as to achieve the gas phase protium dilution, and protium enrichment in solid phase .Results show that compared with palladium thermal displacement method, under the same processing time and the loading amount of palladium, by about 10 times the separation ability, product gas extraction efficiency from 40% to 60%, greatly reduce the intensity of the operating staff and improve work efficiency.