The invention discloses a method for shrinking an overlength bush, which comprises the steps of: S1, heating the overlenght bush; and S2, sleeving the heated overlength bush on a long shaft which is straightened and horizontally aligned before carrying out the step S1, wherein under the condition that the overlenght bush is heated by energizing, the sleeving by energizing comprises the step of: supporting the middle of the long shaft by using a bracket; S22, horizontally hanging the electrified overlength bush and horizontally calibrating the overlength bush and calibrating the axis of the overlength bush; S23, sleeving the overlength bush and supporting the exposed center at the tail end of the long shaft; S24, dismantling the bracket and horizontally sleeving the overlength bush on the long shaft; and S25, uniformly deenergizing the overlength bush. The method has the advantages of safe operation, low cost and accurate shrinking alignment.