Abstract: A method and a system for optimizing operating swing of a vertical shaft suspended hydrogenerator unit, and the method includes: measure turning swing and operating parameters of the unit during turning, calculate direction of relative displacement between the rotating center of each bearing for the unit and a center line of a main shaft, and calculate and adjust offset distance of an installation center for a guide bearing to a certain direction by the temperature of a bearing bush; then carry out a temperature rise test of the unit, optimize the operating swing of the hydrogenerator unit while the bush temperature is less than the design requirement, and select optimal bush gap to achieve optimal operating swing and ensure that the bush temperature, the cooling oil level, the cooling oil temperature and the operating swing reach the most scientific and reasonable balanced state.