Abstract: The retention capacity of helium in reactor materials is one of the key factors to assess their safety performance.In this paper,the basic principle and experimental method of elastic recoil detection（ERD） analysis were presented that the energy spectra of helium can been obtained by elastic recoil detection of ion beam.And the analysis of helium content and depth distribution in thin film can been achieved.With 12MeV carbon ion as a probe,helium in zirconium film was elastically recoiled forward.The content and depth distribution of helium were obtained by analyzing the energy spectra.The helium content of film material annealed at different temperatures was detected for comparison.