A novel optimization method was presented according to the integral carbon fiber bracket of the clamping locking device for a magnetically suspended flywheel. To be equivalent to the cantilever beam model, static and dynamic analyses were performed for the carbon fiber bracket. Its five mechanics performances were obtained, including the maximum interference friction force, locking/unlocking force, the maximum bending stress and first resonance frequency. Sensitivity analysis of the carbon fiber bracket was carried out based on the finite element method. According to the analysis results, two groups of mutually independent structure parameters were obtained. From this, two parts of the carbon fiber bracket were separately optimized. The results show that the mass of the bracket has a minimum of 60.5 g corresponding to 12 slices, which is 64% less than the initial mass of 170 g. Based on optimal results, a locking device was manufactured and its protective effect for the magnetically suspended flywheel was verified by swept-sine vibration and random vibration. The verification shows that the maximum displacement between the stator and rotor is 50μm, which is less than the flywheel system protective gap of 200μm. This indicates that the locking device can effectively carry out the locking protection function for the flywheel system.