Foundation pit drainage device

The utility model discloses a foundation pit drainage device which is arranged in a drainage opening of a foundation pit and comprises a device base body used for being fixed in the drainage opening, a containing cavity used for containing filtered sundries is formed in the device base body, a water inlet and a drainage opening which are respectively communicated with the containing cavity are further formed in the device base body, the water inlet is communicated with the foundation pit, and the drainage opening is communicated with the drainage opening. A filter plate used for filtering water discharged from the water outlet is arranged in the water outlet, and filter holes allowing the water to penetrate through are formed in the filter plate. The filter plate is also connected with a cleaning mechanism for cleaning sludge in the filter holes, and the cleaning mechanism comprises a cleaning roller which slides and rolls, so that the cleaning roller rolls and is inserted into the filter holes when the clean