Abstract: To address the difficulties in accurately predicting deployment-locking impacts of large-inertia solar arrays and the insufficient consistency between ground tests and on-orbit conditions, a ground testing method integrating gravity unloading, velocity compensation, and multi-dimensional impact measurement was proposed. Based on the principle of energy conservation, counterweights were employed to compensate for energy losses caused by the work of non-conservative forces such as friction and aerodynamic resistance, thereby ensuring consistency between ground and on-orbit conditions in deployment time, terminal velocity, and locking impact loads. A two-link dynamic model was established, and an integrated measurement system incorporating vision-based motion measurement, strain measurement, and six-axis force measurement was developed. Test results of a 120 kg-class solar array showed that the proposed method effectively reproduced the 15 s on-orbit deployment process. The maximum impact force in the y direction was measured as 280 N, and the peak impact torque about the z axis was measured as 412 N·m. The deviation between simulation and experimental results was 2.4%, and the repeatability deviation was less than 5%. These results show that the impact energy is primarily transferred along the tangential deployment direction and dissipated through deformation of the root hinge. The proposed method provides technical support for high-fidelity ground verification of deployment-locking impacts of large-inertia solar arrays.