Abstract: Global energy scarcity continues to intensify, and concentrated solar power (CSP) has emerged as an effective low-carbon pathway for large-scale renewable electricity generation. Among CSP technologies, solar tower power generation (STPG) systems are particularly attractive due to their high optical concentration ratios, large thermal energy storage capacity, and ability to deliver dispatchable power at scale. Among various power-block configurations, supercritical carbon dioxide (SCO₂) recompression Brayton cycle–based STPG (SCRBC-STPG) systems have received increasing attention because of the favorable thermophysical properties of SCO₂,compact turbomachinery, and their potential for high thermal efficiency. Despite these advantages, many existing SCRBC-STPG configurations suffer from relatively high levelized cost of electricity (LCOE) and insufficient overall generation efficiency, which hinder large-scale commercialization and practical deployment.To overcome these challenges, this study proposes an integrated configuration that couples a steam Rankine cycle (SRC) with an SCRBC-STPG system, hereafter referred to as SCRBC+SRC-STPG. The SRC is designed to recover residual thermal energy from both the SCO₂ Brayton cycle and the molten-salt thermal energy storage subsystem. By extracting additional low-grade heat, the SRC lowers the required operating temperature of the low-temperature molten-salt tank, thereby enhancing the effective thermal storage capacity. System modeling and simulation were conducted using the EBSILON Professional platform to develop both a baseline SCRBC-STPG model and the proposed SCRBC+SRC-STPG model. Key subsystems—including the heliostat field, receiver heat transfer, molten-salt storage, and power conversion units—were validated against established thermodynamic principles and published performance data to ensure model reliability.Following model validation, a comprehensive parametric analysis was performed to evaluate and compare the thermodynamic and economic performance of the two configurations over a wide range of operating conditions. The results demonstrate that the SCRBC+SRC-STPG system consistently achieves higher net power generation efficiency than the standalone SCRBC-STPG system. Specifically, at a turbine inlet temperature of 550℃ and a high-pressure turbine inlet pressure of 30MPa, efficiency improvements of 4.97%,are obtained relative to the baseline configuration. From an economic perspective, when the power output of the steam Rankine cycle (PSRC) is limited to 16MW, the SCRBC+SRC-STPG system exhibits optimal performance, achieving an LCOE of 0.814 CNY/kWh, which is 0.091 CNY/kWh lower than that of the conventional SCRBC-STPG system. To reconcile the conflicting goals of enhancing efficiency and reducing the levelized cost of electricity (LCOE), this paper conducts a multi-objective optimization study on the SCRBC+SRC-STPG system, and determines its optimal operation scheme based on a comprehensive balance of system performance and economy. The optimization variables included the cycle flow split ratio, high-pressure turbine inlet pressure, and turbine inlet temperature. The resulting Pareto frontier provides clear design trade-offs and practical guidance for system designers by illustrating the impacts of key parameters on both thermodynamic efficiency and economic competitiveness. In conclusion, integrating an SRC with an SCO₂ recompression Brayton cycle and molten-salt thermal storage significantly enhances the technical and economic performance of solar tower CSP plants. The proposed SCRBC+SRC-STPG concept represents a viable pathway for improving conversion efficiency while reducing LCOE and offers valuable insights for the future design and optimization of high-performance, cost-effective STPG systems.