Abstract: Centrifugal fans are widely used in the ventilation systems of nuclear power plants because of their high wind pressure and high working efficiency. Following a vibration-induced failure, vibration measurement and analysis were performed on the fan at the power plant, and finally located the failure cause on the insufficient base stiffness of the bench and the selection of shock absorber. By calculating the center of gravity and natural frequency of the fan, the bench was re-manufactured to meet the design requirements.