The invention discloses a vacuum tube group for replacing a copper-tungsten contact group of an on-load tap changer, which comprises three vacuum tube group units, wherein each vacuum tube group is a one-phase vacuum tube transitional switching unit; three-phase vacuum tube group units are arranged on the circumference by 120 degrees; and each phase vacuum tube transitional switching unit consists of four vacuum tubes which are distributed according to the circumference. The on-load tap changer generates electric arc only in the vacuum tube during switching without generating electric arc outside the vacuum tubes, thereby no electric arc is generated in an oil chamber of the on-load tap changer and oil of insulated transformer in the oil chamber cannot be polluted by electric arc; and the invention can maintain the insulating performance of the oil in the transformer for a long term, greatly reduce the fault rate of the changer, simultaneously reduce the maintenance of the changer and material loss and prolong the service life of the changer and the transformer.