This paper constructs the price formation mechanism of renewable electricity with three pricing mechanisms, namely, system marginal price (SMP), zonal marginal price (ZMP) and nodal marginal price (LMP), on the basis of electricity price location signal. Through the objective function of the constructed optimal dispatch model of renewable energy power, we calculate the minimum operating cost of each power plant under multi-market synergy and use the C&CG column constraint method to solve the price fluctuation caused by the uncertainty of wind and light. Finally, the multi-market synergy rate of the model is estimated by combining the 500 kV, 300 kV and 200 kV unified wind turbines invested by a provincial grid company in China. The results show that the multi-market coordination coefficients α of wind power and photovoltaic projects are 0.1148 and 0.2849, respectively, and the renewable electricity decreases from 0.355 Yuan/kWh to 0.298 Yuan/kWh in 2025 under the optimal dispatch model of electricity. This paper has certain theoretical value and practical reference significance for future renewable energy power price reform.