Abstract: Optimization research was conducted on supercritical carbon dioxide recompression cycle system applied to the fourth generation gas-cooled reactor. By establishing a comprehensive thermodynamic and exergoeconomic model, and introducing spatial compactness indicators based on the demand for nuclear power modularization, a study was conducted on supercritical carbon dioxide recompression cycle system from multiple dimensions such as thermodynamic performance, spatial compactness, and exergoeconomic performance. Impact of key parameters on the performance of supercritical carbon dioxide recompression cycle system was analyzed, and further multi-objective optimization was carried out to improve the applicability of the system. Results show that through multi-objective optimization, the comprehensive performance of the cycle is improved, and the optimal exergy efficiency, unit power cost rate, and required heat exchange area per unit output power are 71.5%, 3.11 cent/(kW·h), and 0.191 m²/kW, respectively.