Under normal circumstances, a high voltage motor stator winding of the inner and outer corrosion is mainly due to the long-term motor operation process electromagnetic vibration, high temperature and high pressure caused by corona corrosion machine vibration and wear of the insulation and thermal aging, and led to the strip coil insulation overall, layered, burning, wear and tear, dielectric strength is reduced, resulting in failure of insulation breakdown, etc. All kinds of mechanical vibration produced in the operation of high voltage motor will wear away and erode the coil insulation, the most important of which is the effect of electromagnetic vibration on the end winding and notch of the motor. If the quality of the customized iron core pressing is not good, the binding process of the wound broken piece is not good, and the coil is not fixed well in the groove, which results in a large vibration, the interlayer gasket strip and the temperature measuring element gasket strip will move back and forth between the upper and lower coils, thus wearing the upper and lower coils and damaging the main insulation of the coil. More seriously, if the current flowing through the conductor during the operation of the coil produces dual-frequency electromagnetic vibration, the coil will not vibrate with the iron core and the spacer at the end of the winding. Therefore, electromagnetic vibration is the main cause of external corrosion and internal corrosion damage of the main insulation of the high voltage motor coil.