Abstract: To address the challenges of complex asteroid geometries, low modeling efficiency, and unclear momentum transfer mechanisms during hypervelocity collisions, a voxelization modeling method accelerated by a Bounding Volume Hierarchy (BVH) structure was developed. Key momentum transfer laws under hypervelocity impact were computationally analyzed using the Smoothed Particle Hydrodynamics (SPH) method. The results demonstrated that compared to GPU-based voxelization methods, the present approach achieved an 86.8% efficiency gain in voxelization processing, with an voxel identification accuracy of 96.5% and particle mass errors below 3.5%. A strong correlation existed between impact angle and momentum transfer factor (β), peaking at β = 3.82 for a 60° impact—representing a 41.7% increase over the 30° impact case. Ejecta-induced recoil contributed 68.3% of the total momentum change imparted to the asteroid. This study confirms that the BVH-accelerated voxelization method efficiently handles concave geometries (7.3 times faster than conventional methods) and identifies 60° as the optimal impact angle for maximizing momentum transfer efficiency in rubble-pile asteroids (β > 3.5). The established technical framework is scalable to kilometer-scale celestial body deflection scenarios, providing critical tool support for optimizing multi-impactor collaborative trajectories.