Abstract: In this paper,the conventional and impregnating properties of the polyetherimide extruded winding wires are studied. The main performance is in accordance with the requirements of GB/T 6109. 6—2008 Enameled round winding wire Part 6: 220 grade polyimide enamel copper round wire. In this study,three impregnating varnishes were selected for impregnation,the first is silicone impregnating varnish（ TH-260 NS）,the second is F-class motor with imine epoxy impregnating varnish,the third is modified imine epoxy impregnating paint. The test results are as follow: After impregnation with TH-260 NS paint,the insulation cracking is very obvious. After impregnation with the imine epoxy impregnating varnish for the F-class motor,the breakdown voltage of the sample is the highest. After impregnation with the modified imine epoxy,there is almost no change.