Machining center spindle positioning device

The invention relates to the technical field of spindle positioning, in particular to a machining center spindle positioning device which comprises a groove box, a plurality of positioning blocks are fixedly arranged in the groove box, a positioning ring is fixedly arranged at the center of the upper surface of each positioning block, and a plurality of integrally-formed through holes are formed in the surface of each positioning ring. An anti-skid gear is fixedly arranged at the center of the positioning ring in a penetrating manner; an integrally-formed through hole is formed in the center of the lower surface of the fixing frame, a second electric telescopic rod is fixedly arranged on the inner wall of the through hole, and an anti-skid arc plate is fixedly arranged at the inner wall end, away from the through hole, of the second electric telescopic rod; the device has the beneficial effects that an external workpiece can be arranged on the outer surface of a positioning block in a sleeving mode, the workp