Abstract: To address the poor toughness and insufficient controllable rupture performance of traditional fragile covers, this paper designs and fabricates a composite cover material with a “flexible matrix–fiber reinforcement layer” structure, which exhibits good hydrophobicity. The material uses polyurethane with predesigned weak zones as the matrix and PTFE‑coated aramid fabric as the reinforcement layer, combining relatively high strength with surface hydrophobic properties. Experimental results show that the static water contact angle of the aramid reinforcement layer reaches 151.9°, demonstrating good hydrophobicity, wear resistance, and seawater corrosion resistance. The burst strength of the cover material reached up to 2889.19 N, which is an increase of approximately 126.8% compared to that of the single flexible matrix. The bursting process further verifies its controllable rupture behavior: during rupture, the cover closely conforms to the projectile model, and the crack propagates directionally along the predesigned weak zones. Except for the arc‑shaped weak zones around the rupture opening, the remaining portion is effectively and reliably tethered without significant outward expansion. This study provides an effective solution for developing new protective devices that are lightweight, highly reliable, and possess controllable rupture characteristics.