Abstract: The mission of returning extra-terrestrial objects has been carried out in many foreign countries.The first returning samples mission in China is the Chang’e V detector,it is about to collect and return lunar samples.Reliable sample sealing technology is to maintain the original state of the extra-terrestrial samples and to analyze data on ground accurately.This paper describes a vacuum sealing technology which is indium alloy and knife-edge as primary vacuum seal and silicon rubber as redundant seal against primary seal failure to seal the extra-terrestrial sample.Results have been verified by ground environment experiments,and results show that the seal leakage rate is better than 5×10^-9Pa·m³·s^-1.This sealing structure can prevent samples from being contaminated.