The invention relates to a cut-off device, in particular to a high-efficiency nail cut-off device for hardware. In order to achieve the technical purposes that the high-efficiency nail cut-off device for hardware is good in cut-off quality, good in application effect and convenient to fix in the cut-off process, the high-efficiency nail cut-off device for hardware comprises a placement plate, a fixing block, a cutter, a lifting rod, a first connecting rod, a first piston, a second piston, a second connecting rod, a third piston, a fourth piston, a cylinder body, a rack, a motor, a sliding rail, a sliding block, a support and a gear, wherein the sliding rail is arranged on the left side in the support, the sliding block is arranged on the sliding rail and provided with the rack, and the motor is arranged on the right side in the support. The high-efficiency nail cut-off device for hardware achieves the effects of the good cut-off quality, good application effect and convenient fixation in the cut-off process, thereby being high in cut-off speed, reasonable in design and convenient to apply and being a device with high practicability.