A paper clearing device for a shredder includes a frame, a motor, a gear set, a first rotary shaft, and a second rotary shaft. The first rotary shaft and the second rotary shaft are mounted with several cutting blades and paper guides. The paper guides on at least one rotary shaft are half paper guides. When paper jams in the shredder, the user only needs to issue a paper back command, which causes the rotary shafts to rotate in a reverse direction, causing paper to back away from the cutting region between the cutting blades and instead pass over the respective shaft with the half paper guides, optionally with the assistance of a paper clearing driver, and through an opening at the back, non-cutting side of the respective shaft to fall into a trash bin from which the jammed paper can be readily removed.