The invention discloses an inductor used in quenching of a large-scale forged steel supporting roll. The inductor used in the quenching of the large-scale forged steel supporting roll comprises an induction coil (1) made of a copper plate, wherein a surrounding cooling water pipe (2) is arranged at the outer side of the induction coil (1), and connecting pieces (4) used for connecting the inductor with an induction transformer are arranged at the two end parts of the induction coil (1). The inductor used in the quenching of the large-scale forged steel supporting roll comprises the induction coil made of the copper plate with a certain width, a plurality of thermometer holes formed in the induction coil, a cooling water pipe which is wound at the outer side of the induction coil and made of a plurality of square copper pipes, a cooling water pipe connector, a fixed support, an insulating plate and connecting pieces connected with the induction transformer, so that the inductor used in the quenching of the large-scale forged steel supporting roll is firm in structure and strong in induced vibration resistance, temperature can be conveniently measured, height of the inductor is increased to 200-250mm from 150-165mm in convention, heating time can be prolonged for 2-4 minutes, heating depth is increased, and depth of a hardening layer of the roll is increased.