Solar energy and wind power need to be equipped with large-scale energy storage devices to suppress power fluctuations. The cost of available energy storage equipment is relatively high, which needs to be developed and innovated. The solar thermal power generation system has good flexibility in energy storage. It can store heat or cool. Heat and cold are used in the hot end and cold end of thermal cycle respectively. In view of the remarkable increase of supercritical CO₂ cycle efficiency with the decrease of cold end temperature, and the low boiling point temperature of working substance, there is a large room for cooling. The concept of supercritical CO₂ cycle solar thermal power generation system with cold storage is proposed, which indirectly stores surplus new energy power through refrigeration. Thermodynamic analysis of supercritical CO₂ cycle with main parameters of 550 ℃/20 MPa and 700 ℃/30 MPa respectively shows that the energy storage capacity of the above system can reach 10% of the power generation capacity of solar thermal power station, and the energy storage efficiency can reach more than 60%. The preliminary economic analysis shows that the system can recover the investment of energy storage equipment for about 3 to 5 years, and has good economy.