The utility model discloses a supporting device for a large-shaft centre hole detection device. The supporting device comprises a supporting device and a lifting probe, wherein the supporting device is a pneumatic supporting device (9); and the lifting probe is a pneumatic supporting probe. In the supporting device of the large-shaft centre hole detection device provided by the utility model, the pneumatic supporting device is adopted; the supporting device for the large-shaft centre hole detection device is not influenced by the Hooke's law compared with the conventional supporting device adopting spring support, so that constant supporting force is kept in centre holes with any diameters; and the operation of a crawling device is facilitated. The probe also adopts the pneumatic lifting probe, namely the probe contacts with the inner wall of a centre hole under a pneumatic action; the operation is reliable, and the supporting device is easy and convenient; and the pneumatic lifting probe is better than a spring supporting probe.