The impeller is the core component of the centrifugal compressor. Aiming to solve problems related to a large mass, high energy consumption, and large vibration of the existing centrifugal impeller, a semi-open supersonic centrifugal impeller provided by Krain et al. was redesigned in this paper. The redesign was based on Tsai-Wu failure theory and the two-way fluid-structure coupling method. Firstly, the geometric and numerical models were established using the geometric data found in the literature. Then, the established geometric and numerical models were verified through experimental data. Finally, the impeller was optimized from three aspects: material lightweight, composite material layering, and tip clearance. The results have shown that following the optimization, the maximum impeller stress was reduced by 48.77% when compared to the traditional 17-4PH material impeller. The maximum vibration deformation was reduced by 60.4%, as well as the resonance probability. The pressure ratio was increased by 0.8%, and the pressure and velocity reverse gradient trend near the blade tip were significantly reduced, while the flow field was more stable. The research results presented in this paper hence provide a basis for the application of composite materials in centrifugal impellers.