From the composition analysis of high-voltage motor windings, conductive wire → insulating material → air gap → iron core, together they form a multi-layer, multi-medium capacitor, especially the air gap formed during the coil wrapping process, and the gap between the coil and the iron core slot, the electric field strength is very high. When the field strength reaches a certain level, the air in the air gap will undergo ionization discharge, accelerating the aging of the insulating medium. The oxides produced by the discharge will produce substances that corrode the insulating medium when they encounter moisture, and over time, the insulating material is chemically broken down. For this reason, in the high-voltage motor coil processing technology, it is particularly required that the coil insulation wrapping is tight and smooth, the wire embedding process should try to reduce the gap between the coil and the iron core, and the air gap in the winding should be reduced or eliminated through the varnishing process.