Cleaning tank blocking and filtering device

The utility model discloses a cleaning tank blocking and filtering device, which comprises a flange accommodated in a drainage outlet of a cleaning tank. A blocking part is hung down from the flange and comprises a drainage opening. A flexible membrane extends out of the flange and comprises a perforating part, and the perforating part is sealed by the blocking part in a first structure. A non-perforating part closes the drainage opening. The flexible membrane can be moved to a second structure, and in the second structure, the perforating part can be moved away from the blocking part to allow the water from the cleaning tank to flow through the perforating part. The non-perforating part is moved away from the drainage opening to allow the water to flow through the drainage opening.