Dismounting device for valve stem seal

The utility model discloses a dismounting device for a valve stem seal. The dismounting device comprises an elastic sleeve provided with a screw rod, a compression sleeve and a support sleeve, wherein a first conical surface is arranged on an outer wall of the elastic sleeve, an opening end of the elastic sleeve is used for clamping the to-be-dismounted valve stem seal, and a first nut and a second nut are arranged on the screw rod; a second conical surface matched with the first conical surface in an extrusion manner is arranged on an inner wall of the compression sleeve, the compression sleeve is arranged on the elastic sleeve in a sleeving manner, and the first nut can drive the compression sleeve to axially move for extruding and retracting the opening end of the elastic sleeve; the elastic sleeve and the compression sleeve together penetrate the support sleeve, and the second nut drives the elastic sleeve and the support sleeve to move relatively. The dismounting device cannot damage the valve stem seal and a valve guide pipe and is simple in structure and uniform in stress, and the operation saves labor.