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In order to improve the shielding ability of spacecraft against space debris hypervelocity impact, the B₄C-Al based composites prepared by pressureless presintering and aluminium infiltration in vacuum were designed as the front bumper of Whipple shielding configuration, and the hypervelocity impact tests were carried out on a hypervelocity impact range to evaluate the shielding performance of B₄C-Al bumper and Al alloy bumper under the impact velocity of 3 km/s ~ 6.5 km/s. By comparising the bumper penetration, the rear wall damage state and the debris clould structure of the two different bumper materials under various impact velocity as well as the SEM and EDS results, the relationship among the bumper material properties, the cratering mechanics of rear wall and the debris cloud characteristics was discussed. The research results indicated that the B₄C-Al bumper can break the projectile into smaller pieces and even make the debris melt, and the impact damage of debris cloud on rear wall was alleviated significantly, meanwhile, the good toughness of Al metallic phase can keep this bumper structure intact. Hence, both the pulverized small debris and the decreased impact kinetic concentration of debris cloud are the main reasons to obtain higher shielding capability of B₄C-Al bumper. This primary investigation provided theoretical and technical instructions for the design and application of B₄C-Al based composite materials in space debris shielding configuration.