Twin-cylinder rotary hydraulic shears are powered by hydraulic energy. After starting the equipment, the hydraulic pump draws the hydraulic oil from the tank, pressurizes it and delivers it to the various circuits of the hydraulic system. When shearing operation is required, the high-pressure oil enters the rodless chamber of the double cylinder by operating the reversing valve, pushing the piston to drive the piston rod out, and the piston rod drives the cutting edge to close, generating a strong shearing force to cut the object.