<p>As the total amount and share of new energy installed capacity continue to rise, the demand for flexible regulation capability of the power system is becoming more and more prominent. The current conventional molten salt energy storage system has insufficient peaking capacity. A solar-molten salt energy storage system based on multiple heat sources is constructed in this study. The heat generated from the solar field and the steams are used for the peaking process to further enhance the peaking capacity and flexibility. The installation multi-stage steam extraction and the introduction of an external heat source significantly improve the system performance. The simulation models based on EBSILON software are developed and the effects of key parameters on performance are discussed. The feasibility of the proposed system is further evaluated in terms of exergy and economy. The results demonstrate that the proposed SF-TES-CFPP (solar field, thermal energy storage system, coal-fired power plant) system exhibits the enhancement of peaking capability and flexible operation. In comparison with the conventional TES-CFPP, the integration of solar energy into the peaking process has enabled the SF-TES-CFPP system to enhance its peaking capacity by 20.60 MW while concurrently reducing the coal consumption rate by 10.26 g/kWh. The round-trip efficiency of the whole process of the system can be up to 85.43% through the reasonable heat distribution. In addition, the exergy loss of the principal components can be diminished and the exergy efficiency of the system can be augmented by selecting an appropriate main steam extraction mass and split ratio. The economic analysis demonstrates the dynamic payback period is 9.90 years with the net present value (NPV) across the entire life cycle reaching 1.069 02×10⁹ USD.</p>