Step by step fill procedures for thin-wall hollow micro-sphere was applied. The leakage of the metal system was 3.7×10-4Pa L/s under the pressure of 15MPa. U and LaNi5 combination serve as good gas-resource，supplying high pressure. Both at the room temperature and 250℃, the shell can bear 1.0MPa and the pressure ratio of inside to outside was about 0.51. At 250℃,the pressure of D-T filled into the spheres was 0.51-0.54MPa,which satisfied the physical experiment requirement.