Abstract: The electromagnetic vibration of hydro-generator stator may lead to stator winding insulation wear, stator core loosening, electrical corrosion, tightening screw fatigue fracture and stator anchor bolt damage. To prevent the insulation failure or even serious damage of hydro-generator caused by these problems, this paper introduces the concept of unit motor to calculate the vibration amplitude of the core, and analyzes the electromagnetic vibration of the stator of #1 hydro-generator in one 110 MW power station, and puts forward a feasible transformation scheme. Finally, the field test is used to verify the elimination effect of the transformation scheme on the electromagnetic vibration of the stator of the motor.The results show that the electromagnetic vibration of the stator of #1 turbine generator in hydropower station is mainly caused by the excitation caused by the interaction between the reversed 26th and 38th stator magnetomotive force harmonics and the main wave magnetic field. After the transformation scheme with 528 slots, the minimum effective values of vibration velocity under no-load, rated load and 100 Hz are 0.03, 0.01 and 0.01 mm/s, respectively, which are 85%, 95% and 43% lower than those of the corresponding positions（ upper frame horizontal, lower frame vertical and lower frame vertical） before the transformation, and the transformation effect is obvious. The methods and strategies described in this paper are of great significance to guide the development of stator electromagnetic vibration control of hydropower units and ensure the long-term safe and stable operation of the units. At the same time, it provides a decision-making basis for the analysis and transformation of stator electromagnetic vibration of hydro-generators at home and abroad.