The invention provides a hole pattern calibrating device for a mandrel pipe mill. The hole pattern calibrating device for the mandrel pipe mill comprises a base, a cover plate, a guide rail, a stop block, a lifting cylinder, a positioning block, a hole pattern pipe, a high-precision displacement cylinder and an electrical system, wherein the cover plate, the guide rail, the stop block, the lifting cylinder, the positioning block, the hole pattern pipe and the high-precision displacement cylinder are all mounted on the base, and the electrical system is connected with the high-precision displacement cylinder; the high-precision displacement cylinder can change the position of a roller of a roller rack till the roller is in contact with the hole pattern pipe, and a displacement sensor arranged on the high-precision displacement cylinder can record the displacement of the high-precision displacement cylinder and output the displacement to the electrical system; and the electrical system can change the corresponding original position of the roller of the roller rack according to the displacement, and thus a standard hole pattern is obtained. The hole pattern calibrating device for the mandrel pipe mill can solve the problem disclosed in the background technology that, at present, the wall thickness of a rolled seamless steel pipe is uneven because of existing of errors of hole patterns.