Abstract: To decrease the parasitic power required for the air compressor and enhance the fuel cell system's overall efficiency for high-power fuel cell system, a comprehensive model encompassing electrochemistry, kinetics, and thermodynamics was developed based on recovering cathode exhaust energy of a radial turbine. Firstly, the intercooler performance prediction model was corrected based on the NTU-ε method with improved accuracy. And then, the performance of cathode exhaust gas energy recovery was investigated for radial turbine under the influence of single-stage and sequential compression-energy recovery modes. The results show that the overall energy recovery efficiency tends to decrease as the stack loading current increases. Compared to the single-stage compression-energy recovery model, the sequential compression-energy recovery model demonstrates a significant enhancement in energy utilization at both rated and non-rated operating points. Implementing optimized operational strategy, the energy utilization rate of cathode exhaust gas can be improved up to 28.9% and system efficiency can be improved up to 2.79%.