One key tast of the third phase of China’s Lunar Exploration Project is to collect lunar sample and return to the Earth.Sealing technology is used to maintain the original state of lunar sample and ensure the reliability of ground analyzing based on lunar samples.According to the requirement of lunar sample sealing and data analyzing,a structure of sealing lunar sample by using indium alloy and knifeedge as primary vacuum seal and silicon rubber as redundant seal against primary seal failure is proposed，and some relevant experimentation of sealing structure is carried out.Experiment result shows that this optimized sealing structure can be used to seal lunar samples without being contaminated.