Abstract: In order to improve the efficiency of the Wind-Solar-Hydropower joint generation system, an operation optimization method for this system based on the Northern Goshawk Optimization (NGO) algorithm is proposed. Taking the maximization of the electricity-selling revenue of the joint generation system as the objective function, and comprehensively considering the operation constraints of wind farms, solar power plants, and hydropower stations, an operation model of the joint generation system is established. The NGO algorithm is employed to solve this model. Through case-based analysis, the effectiveness of the NGO algorithm in optimizing the operation of the joint generation system is verified.