Currently, cable inspection operations are highly dependent on manual procedures, and efficient automated inspection methods are lacking. To address this issue, a cable gripping mechanism for electrical cabinet inspection has been designed. The mechanism was developed to meet the requirements of controllable gripping force, multi-specification cable adaptability, and rapid tool replacement. The kinematic characteristics of the gripper were analyzed based on geometric constraints, and static analysis and topology optimization were conducted using ANSYS. A prototype platform was established, and gripping tests on RV 1 mm², RV 1.5 mm², and BVR 4 mm² cables, as well as pressing tests on difficult-to-inspect cables, were performed. The results show that the proposed mechanism can grip cables with outer diameters of 2.4–4.8 mm. After topology optimization, the fingertip volume was reduced by 11.54%, improving adaptability to confined spaces. The maximum stress and deformation were 78.486 MPa and 0.017626 mm, respectively, satisfying the design requirements. No cable damage, slipping, or detachment was observed during inspection, and the gripping marks could recover naturally. The proposed mechanism can meet the requirements of automated cable inspection in electrical cabinets.