Concentrated solar power plant(CSP) with thermal storage system has good flexibility and schedulability, which can effectively improve regulation level and renewable energy accommodation of power system. Firstly, based on the operation mechanism of CSP with thermal storage system, the operation model of CSP with heat storage and electric heater is developed to describe the energy conversion characteristics and operation constraints of CSP. Furthermore, with the aim of minimizing the comprehensive cost of the system, considering the operation constraints of the system, the optimal dispatching model of power system with large-scale wind power and CSP is proposed and solved by optimization software CPLEX. The model comprehensively considers reserve capacity provided by CSP, operation stability and economy of the system, for which the optimal day-ahead scheduling strategy is obtained. The feasibility and effectiveness of proposed method are verified by example results of IEEE 39-bus system.