The invention relates to a paper processing product and, in particular, to a shredder that crinkles paper stripes. The shredder has a shaft set driven by a motor. The shaft set includes at least two shafts rotating in opposite directions. Cutting blade sets are mounted on the shafts. Paper enters the entry of a paper passage formed by the shafts, and gets shredded into chips by the cutting blades. Since the exit of the paper passage is provided with a movable stopper, paper stripes are pushed by the rotating cutting blades to pass the stopper and become crinkled. The stopper is triggered to open by a certain force, letting the paper stripes fall. In addition to the functions of a usual shredder, the paper stripes thus made can be recycled.