Drainage device

The utility model provides a drainage device. The drainage device comprises a supporting frame; the drainage frame is arranged on the supporting frame, and a water inlet groove is formed in the drainage frame; the lower filter screen assembly is fixed at the end part of the water inlet tank, and a first filter hole is formed in the lower filter screen assembly; the floating filter screen is arranged in the water inlet tank in a sliding mode in the first direction and is close to the end of the water inlet tank, and second filter holes are formed in the floating filter screen; the upper floating filter screen can float up and down and move relative to the lower filter screen assembly, so that the top end of the lower filter screen assembly can remove blockages of the second filter holes. The lower filter screen assembly and the upper floating filter screen are arranged, and the upper floating filter screen can float up and down. Therefore, the top end of the lower filter screen assembly and the second filter h