Accidental impacts affect the structural integrity of umbilical cables during their life cycle. This study investigates the impact behavior of a steel tube umbilical cable using both experimental tests and numerical simulations. A series of impact tests are carried out to elucidate the failure modes and deformation responses of non-bonded multi-layer components. A three-dimensional finite element model is established and verified to capture time-history responses. Through the analysis of time-history responses, the impact energy dissipation mechanisms are investigated, and the impact resistance of armor layers is further evaluated. It is found that the armor layers and polymer sheaths dissipate only approximately one-third of the impact energy, demonstrating limited protection capability, while more impact energy is absorbed by internal functional components. The steel tube may have sustained severe damage, even though the armor layer and polymer sheath exhibit only minor damage. This work has provided a reference for the damage assessment and protection design of umbilical cables.