A hybrid power plant composed of wind farm, concentrating solar power station and biomass boiler can effectively improve overall operating income while participating in the power market. The study focuses on the integration of the hybrid power plant in the electricity market. A robust optimal scheduling model for wind power-concentrating solar power-biomass hybrid power plant is proposed based on the structure and operation mechanism of the plant. The model takes maximizing operating profit as the objective function, and considers the benefits of hybrid power plant participating in the power market, the environmental benefits of parallel operation, the penalty costs of wind abandonment and solar abandonment, the operating and maintenance costs of each component, and the system operation constraints. Given the uncertainty faced by a hybrid power plant and the risks that it entails, a robust optimization approach is used to deal with the uncertainties brought by the wind power, concentrating solar power, load, and electricity market prices. In addition, a risk index system is presented to balance the robustness and economy of the system. This provides a decision-making basis for hybrid power plant operators. The numerical examples verify the effectiveness of the proposed model and method. This work is supported by the National Natural Science Foundation of China (No. 52077060).