Shaft hole centering device and method

The invention relates to a shaft hole centering device and a shaft hole centering method. The device comprises a base, a limiting device, an elastic device and a driving device, wherein the base is provided with a first mounting hole for accommodating a top pin; the limiting device is fixedly connected with the base and is used for limiting the top pin from axially moving in the first mounting hole; the elastic device is wound on the top pin; one end of the elastic device is contacted with the limiting device and the other end of the elastic device is contacted with the top pin; and the driving device is inserted into the central hole of the base, then is contacted with the surface of the top pin and is used for driving the top pin to be ejected out of the first mounting hole through gravity, so that a first end part of the top pin is contacted with the surface of a shaft hole of a centered workpiece. In the device, by adopting a combined positioning mode of the top pin and the driving device, because the top pin extends out of the first mounting hole under the driving of the driving device, and the extending distance is determined by the motive power and positioning pressing force provided by the driving device, the size of a conical hole of the centered workpiece can be changed. Therefore, the centering flexibility is improved.