Automatic centering coiling device and method for hot rolled coil separating line

The invention provides an automatic centering coiling device and method for a hot rolled coil separating line. An encoder is arranged in the operation direction of a coiling reel; limiting switches are arranged on central lines of an inlet stepping beam and a preparation station respectively; a coiling reel automatic positioning control program is added in an addition function control block FC; and the actual stop position D of the coiling reel is set to meet the formula that the D is greater than or equal to L-delta L, but less than or equal to L+delta L. When a stop iron of the coiling reel is in contact with the limiting switch on the stepping beam, the code value of the encoder is cleared; when the stop iron of the coiling reel is in contact with the limiting switch of the preparation station, the initial code value X is recorded; when the coiling reel is stopped, the code value Y is recorded timely, and the position deviation delta L of the coiling reel and the stop position D of the coiling reel are cal