The invention relates to a straightening device used for a loop tie wire sealing and arrangement machine transferring mechanism. The straightening device comprises a rotary structure and an opening and closing structure which controls a first rack to vertically move along a first fixing plate through reciprocation of a first cylinder. The first rack is engaged with a first sector gear and a second sector gear which separately control left-right movement of a second fixing plate and a third fixing plate. Left-right opening and closing movement of the second fixing plate and the third fixing plate control opening and closing movement of a first disc brush and a second disc brush. The straightening device is reasonable in opening and closing structure design, can achieve a good straightening effect and is low in cost; and according to the rotary structure, a first gear and a second gear are designed, so that the first disc brush and the second disc brush rotate in opposite directions, and a motor output shaft and a third spindle conduct perpendicular transmission through a bevel gear so that the first disc brush and the second disc brush can straighten a conducting wire in the vertical direction.