The utility model relates to the technical field of devices for recovering waste water, in particular to a device for recovering filtering and backwashing water in a tank, which comprises a cyclone concentration cylinder, a flow-diversion inner pipe and supporting legs; and the outer side of the lower end of the cyclone concentration cylinder is fixedly provided with at least two supporting legs, the bottom of the cyclone concentration cylinder is fixedly provided with a sludge collecting and discharging device, a sealing plate is fixedly installed in the middle part of the cyclone concentration cylinder, the middle part of the sealing plate is provided with an installing hole, the upper end of the flow-diversion inner pipe is fixedly installed in the installing hole, a liquid inlet pipe is fixedly installed on the cyclone concentration cylinder at the outer side of the flow-diversion inner pipe, the liquid inlet pipe and the inner wall of the cyclone concentration cylinder are in tangential arrangement, and a valve is fixedly installed on the liquid inlet pipe. The utility model has reasonable and compact structure and is convenient to use. By recycling water discharged by the backwashing of a filtering tank, the wastage of water resources is greatly lowered, and the production cost is lowered.