Straightener capable of changing rolls quickly

The invention discloses a straightener capable of changing rolls quickly. The straightener comprises a driving side frame, a rolling ring assembly, a sliding seat, an operation side frame, a transverse shifting device and an onboard roll changing device, and the on-board roll changing device comprises a roll changing trolley, a lifting device and a rolling ring storage table. The rolling ring storage table is arranged on a lifting device, and the roll changing trolley matches with the sliding seat in a reciprocating slide manner and is arranged on the sliding seat. The onboard roll changing device further comprises a positioning rolling ring storage table and a storage table positioning device opposite to the roll changing trolley in the horizontal direction. When rolls are changed, the rolling ring storage table is lifted to contact with the rolling ring assembly, then a locking device is released from a dragging rod, and the rolling changing trolley and the operation side frame are dragged by the transverse device to move horizontally to separate the rolling ring assembly from the dragging rod, so that the rolling ring assembly and the rolling ring storage table can be hoisted away in one piece. The straightener is simple and convenient in roll changing operation, and short in roll changing time; working efficiency of roll changing and device utilization efficiency can be improved; and the straightener has the advantages of small size, low cost and the like.