Seal ring and puncture cannula with same

The invention relates to a seal ring and a puncture cannula with the same. The seal ring comprises a flexible glue tapered ring body with a through hole at the center, and further comprises a plurality of hard films covering the inner side of the flexible glue tapered ring body, wherein the lower end of the through hole extends out of the lower ends of the hard films. When in use, a puncture instrument is in contact with the hard films, and can not damage the flexible glue tapered ring body; and according to the invention, the elastic flexible glue tapered ring body is in press fit with the hard films, so that the elastic flexible glue tapered ring body can be prevented from being worn and broken due to direct the contact with the point of a puncture cone and is guaranteed to be used normally. When the puncture instrument is drawn out, the flexible glue tapered ring body can not be driven to be turned outwards and can drive the hard films to tighten up and reset inwards due to elasticity. The seal ring provided by the invention can adapt to puncture instruments with different external diameters entering cannulas.