The embodiment of the invention discloses a photocatalyst recovery device, an organic waste water treatment method and an organic waste water treatment device. The photocatalyst recovery device comprises a first end, a second end, a third outlet and a filtering passage, wherein the filtering passage comprises a water inlet end and a water outlet end; the water inlet end is communicated with the first end, and is used for flowing water in which the photocatalyst is not separated; a filtering membrane crossing the filtering passage is arranged between the water inlet end and the water outlet end and is used for intercepting the photocatalyst contained in treated waste water; a filtering opening is formed on the water inlet end side, adjacent to the filtering membrane, of the filtering passage and is communicated with the third outlet; and the water outlet end of the filtering passage is communicated with the second end, and the second end is communicated with a water outlet tank which is used for storing treated water after filtration. The photocatalyst recovery device, the organic waste water treatment method and the organic waste water treatment device, provided by the invention, can reduce the cost of treating the organic waste water.