Inlet liquid filtering device of waste liquid storage tank

The utility model discloses a waste liquid storage tank inlet liquid filtering device which comprises a liquid inlet pipe and a filtering cylinder, a threaded hole is formed in the other end of the liquid inlet pipe, a turncap is rotatably installed in the threaded hole, the filtering cylinder is installed on the lower wall of the turncap, an inserting hole is formed in the side wall of the filtering cylinder, and a connecting pipe is installed on the side wall of the liquid inlet pipe in an inserted mode. The connecting pipe is inserted into the filter cartridge through the insertion hole, a through hole is formed in the upper wall of the turncap, a sliding rod is inserted and mounted in the through hole, and a rubber plug is mounted at one end, positioned in the filter cartridge, of the sliding rod. The filter cartridge is mounted on the turncap, so that when the filter cartridge needs to be replaced, the filter cartridge can be taken out of the liquid inlet pipe only by screwing out the turncap; in additio