The invention relates to the field of hardware machining equipment relevant technology, in particular to a high-efficiency polishing device for hardware machining. The device comprises a machining frame, a polishing head, a spraying head and a connecting pipe, wherein a pneumatic support is slidably connected to the inner wall of the machining frame, a connecting plate is welded to the interior ofthe machining frame, two outer filter screens are clamped inside the connecting plate, a clamping groove is formed inside the connecting plate, an elastic clamping plate is clamped inside the clamping groove, an elastic clamping block is clamped inside the connecting groove, and a water storage tank is arranged at the lower end of the connecting plate. The device has the beneficial effects that water sprayed by the spraying head is in contact with the outer filter screens through a polishing table, is filtered through the outer filter screens, and then is filtered secondarily through inner filter screens, the filtered water re-enters the water storage tank, water resources are saved, cyclic utilization of the water is realized, so that the utilization efficiency of the water is improved,the outer filter screens adopt a clamped fixing structure, so that mounting and dismounting are facilitated, and the device is suitable for popularization.