<p>Hyper-redundant robots are widely deployed in confined environments, but the structural characteristics render them vulnerable to environmental disturbances. Ensuring operational safety necessitates the analysis of the robot’s posture-dependent disturbance resistance. While existing methods primarily evaluate operational performance, they fail to characterize the transmission of disturbances across joints. To address this limitation, this paper proposes a novel metric, the disturbance hyper-ellipsoid (DHE), comprising the error hyper-ellipsoid and the shock hyper-ellipsoid. This metric describes the transmission of external disturbance from Cartesian space to the joint space. Specifically, disturbances are modeled as unit spheres at Cartesian space, transformed into the joint space, and projected as ellipsoids for analysis. Both simulations and experiments validate a correlation between DHE, joint errors, and accelerations. The proposed method estimates joint-level sensitivity, facilitating an evaluation of the robot’s disturbance rejection capability. Furthermore, incorporating DHE as an optimization objective in trajectory planning proves to be a promising strategy for enhancing posture stability and operational safety.</p>