As an important component of spacecraft, if a gas-filled pressure vessel is impacted by space debris, it might occur even overall bursting. Spherical aluminum projectiles are used to simulate space debris impacting gas-filled spherical pressure vessel with hypervelocity. Projectiles impact places with the same thickness in different tests. By analyzing the maximum gas pressure of the spherical vessel, the inflation pressure is determined: 1.075MPa. By numerical simulation, the critical impact velocity to perforate the front wall is determined: 2.02mm ~ 2.31mm. As the projectile velocity increases, the damage patterns of the back wall are of different bulged outwards patterns.