Abstract: In view of the problem that wind-solar grid integration will reduce the system inertia and weaken the system frequency regulation capability,considering the synchronous inertia of hydropower generators,the virtual inertia and droop control of wind farms and PV stations comprehensively,the dynamic frequency response model of multi-machine system with wind,solar and hydropower is proposed. The rate of change of frequency constraint,nadir frequency deviation constraint,as well as quasi-steady-state frequency deviation constraint,is deduced. Based on above,in order to maximize the utilization of clean energy,the goal is to minimize the amount of abandoned wind,solar and hydro power and maximize the stored energy of hydro stations at the end of the scheduling period.considering the multiple operational constraints of cascade hydropower,wind power,photovoltaics and the system,the short-term optimal scheduling model for the wind-solar-hydro coordinated generation system is constructed,and the mixed integer linear programming method is used to solve it. Finally,the simulation examples verify the validity and applicability of the proposed model.