Abstract: With the promotion of the carbon peak and carbon neutrality goals, the demand for peak shaving and frequency modulation in the grid is rapidly increasing. To better play the role of compressed air energy storage (CAES), this paper proposes a trigenerative CAES system coupled with a thermal power plant. Based on the established thermodynamic models and the techno-economic analysis models, the system thermal performance as well as economics performance are evaluated, and the influences of key parameters on the economic indicators are analyzed to provide guidance for future practical engineering application. The results show that the new system efficiency is enhanced by 16.21% and 5.39 tons of coal are saved for one cycle under a typical condition. Besides, the dynamic payback period is shortened by 11.8 years, and the internal rate of return is increased by 5.72%. These results demonstrate that the proposed new CAES system has better performance in both thermo-economy and techno-economy. The parametric sensitivity study indicates that the system is greatly affected by the number of annual cycles and the peak shaving subsidy range. When the number of annual cycles is less than 190, the peak shaving subsidy boundary is less than 35.5% load rate or the electricity subsidy is less than 0.14yuan/kW·h, the coupling system will not be investable. This study provides a new development idea for the large-scale commercial promotion and application of CAES, and also provide reference and basis for investors.