PURPOSE: To eliminate a tube rotating device and to reduce a rolling cycle time by concurrently performing reverse transfer and turning by a prescribed angle by reversal rolls given an adjusted skew angle after a 1st rolling for a tube stock in plug mill rolling.

CONSTITUTION: As for tube rolling, a motor 15 is actuated, a skew angle of a reversal roll 4 is adjusted to a required value determined by a length and outside diameter of a tube stock A. Then, an elevating table 11 is actuated by an elevating cylinder 16 and both reversal rolls 4 are rotated under a condition in which a distance between both the rolls 4 is larger than an outside diameter of the stock A. At that time, mill work rolls 1 having a mill opening necessary for rolling are rotated and driven to supply the stock A to perform a 1st rolling. Then, the mill work rolls 1 are opened, the rolls 4 are closed by the cylinder 16 to pinch the stock A and return the stock A by giving rotations corresponding to a skew angle provided for the rolls 4. Further, the rolls 4 are opened and the rolls 1 are closed to perform a 2nd rolling.