A depinching mechanism including a frame, a star wheel assembly, a transmitting device and a sensor is provided in present invention. Through the transmitting device rotating reversely, the star wheel assembly is lifted to the second position when paper jam occurs, thus depinched the media so that user can clear the paper jam. After that the star wheel assembly is lowered to the first position again. The star wheel assembly remains in the first position in normal printing process. Using a one-way clutch and a cam with an outer predetermined profile, the transmitting device rotates forwardly without transmitting any torque during normal printing process, and rotates inversely with transmitting a torque to lift the star wheel assembly up and lower the star wheel assembly down when paper jam occurs. Thus, the depinching mechanism can be used in printers to auto fix the paper jamming problems.