The invention discloses a superconducting conductor special-shaped armor inner diameter detecting device which comprises a short pass go/no-go gauge and a long pass go/no-go gauge. The short pass go/no-go gauge is a cone structure with two flat tops sharing a cone bottom, and the long pass go/no-go gauge is a cylindrical structure. The rear end of the short pass go/no-go gauge is connected with the front end of the long pass go/no-go gauge via a connecting line. The front end of the short pass go/no-go gauge and the rear end of the long pass go/no-go gauge are connected with connecting line respectively. The device adopts the short pass go/no-go gauge slightly smaller than the lower limit of the inner diameter of an inner bore of an armor, effectively tests the inner diameter of the conductor armor, and solves the difficult problem that the inner diameter of the inner bore of the conductor armor is difficult to measure.