Abstract: This paper introduced the helium leak detection method for post-irradiation fuel rods and helium leakage device was designed,including the pressure helium device,suction gun leak detection device and vacuum-chamber leakage device,which was proved to be effective in hot cell.In the experiment,helium leak detection of post-irradiation fuel rod was conducted by suction gun and segment helium leakage device before cutting,and the background was similar to the leakage rate,which indicated that there was no leak source on the fuel rod.During the cutting,helium was detected,which further indicated that there was no leak source.Suction gun helium leakage detection was carried out after cutting,and it indicated that the background was similar to the leakage rate and there was no leak source on the fuel rod.