Method and system for recovering hydrogen isotopes in process waste gas

The embodiment of the invention provides a method for recovering hydrogen isotopes in process waste gas, which is used for recovering hydrogen isotopes in hydrogen isotope-containing process waste gas generated in a radioactive process system, and comprises the following steps: sequentially introducing the process waste gas into an oxidation reactor and a palladium membrane reactor, the oxidation reactor is used for carrying out pre-oxidation treatment on the process waste gas to remove palladium toxic gas in the process waste gas, a palladium membrane is arranged in the palladium membrane reactor, and one side of the palladium membrane is filled with a catalyst; hydrogen is continuously introduced into the palladium membrane reactor, the process waste gas flows on the side, filled with the catalyst, of the palladium membrane, and the hydrogen flows on the other side of the palladium membrane, so that hydrogen isotopes in the process waste gas are replaced into the hydrogen through the palladium membrane and