Abstract: The spacecraft in the low Earth orbit is vulnerable to the hypervelocity impact by micrometeoroids and space debris. Compared with the vertical impact, the oblique impact is more commonly found and worth more research effort for the hypervelocity impacts. In this paper, a numerical calculation is made with the Autodyn-3D software and the smooth particle hydrodynamics (SPH) algorithm to simulate the process of the Al2017-T4 spherical projectile impacting obliquely the Al2A12 plate at an ultra-high speed of 3 km/s to 6 km/s with an impact angle of 0° to 60°. It is shown that the impact angle has a significant effect on the morphology of the debris cloud, as well as on the size and the shape of the perforation hole. With an impact angle between 30° and 45°, the backsplash of the sliding projectile will occur, reducing the penetration ability of the projectile. The above results may provide some guidance for the design and the improvement of the protective structures against the inflight hyper-velocity impact.