Abstract: This paper investigates the automatic generation control (AGC) strategy for vibration zone crossing in large-scale hydropower stations. Aiming at the problems of excessive active power deviation and forced AGC exit caused by the fixed-step and single-unit priority load distribution adopted in the original control strategy, a multi-unit cooperative load sharing control method is proposed. Field tests are carried out to verify the optimized strategy. The results show that the proposed method can effectively reduce the unit active power deviation, eliminate the hidden danger of accidental AGC exit, ensure stable and fast vibration zone crossing of generating units, and significantly improve the operational safety and stability of hydropower stations and power grid dispatching.