Abstract: A method for protecting against high-speed projectile impacts without excessively increasing the areal density of the protective structures was proposed in this paper, based on probability analysis for multiple impacts. Assuming a random distribution of multiple projectiles and neglecting low-probability events, the number of impacts that require protection was identified. Building upon the foundation of effective single-impact protection, an areal density compensation method was presented. A light gas gun test was conducted on 100 cylindrical aluminum alloy projectiles that sequentially impacted a square composite target plate with a side length of 2000 mm. The results indicate that dual-impact protection is sufficient for the tested scenario. An additional layer of aramid/boron carbide (B₄C)/UHMWPE plate with an areal density of 25 kg/m² was incorporated into the existing protective structure, which consists of two layers of aluminum alloy plates and UHMWPE plates with a combined areal density of 37.5 kg/m². The enhanced protective structure was effective in withstanding sequential impacts at velocities of 1.8 km/s and 1.9 km/s. The approach provides a reference for designing protective structures against multiple impacts.