The invention discloses a method for repairing a spindle taper hole through an autogenous grinding device, and belongs to the technical field of machine tool maintaining. The method is mainly used forrepairing work of benchmark losses caused by serious numerical control machine tool spindle taper hole damage. The method is suitable for maintaining of the benchmark losses caused by numerical control machine tool spindle taper hole damage. The structure is simple, stability is good, through machine tool feeding, precise control over each time of grinding amount can be achieved, excessive grinding of the spindle taper hole can be avoided, the maintaining cost is greatly reduced, and the spindle taper hole repairing quality is improved. A base, a guide rail bottom plate, a bearing, a rotationshaft, a guide rail, a feeding drag plate, a screw, a screw support and a hand wheel are included, the motor drives a driving belt wheel to rotate, a transmission belt winds around the driving belt wheel and a driven belt wheel, the hand wheel drives the screw to rotate, the guide rail and the feeding drag plate have a fit structure, and relatively axially move, and the method comprises the stepsof using of an autogenous grinder, machine tool precision detection and grinding wheel grinding path performing.