In order to get the damage mode and resist character of spacecraft shield structure by the high-velocity impact of space debris, a two-stage light gas gun with non-powder projection was used to launch Al-sphere projectiles impacting on aluminum alloy Whipple shield. By analyzing damage mode in different impact velocity ranges, the laws of penetration hole diameter and cratered area diameter depending on projectile diameter and impact velocity were observed. At the same time, the ballistic limit curves of the Whipple shield in a velocity range from 0.5 km/s to 5.5 km/s was obtained. Comparing to the predicted curve from Christiansen ballistic limit equation, the experimental minimum critical projectile diameter is slightly greater than the prediction.