Room air ventilation filtering device

The utility model provides a room air ventilation filtering device, is including being used for filtered air's sky to strain, empty strain to strain including highly the same interior sky strain with the outer space, interior sky is strained to strain with the outer space and is cylindric, the external conjugate diameter that interior sky was strained is less than the interior diameter of straining the outer space, outer space filter ruffle in the outside that interior sky was strained, interior sky is strained and the active carbon is filled between straining to the outer space, cover interior sky is together strained and is strained the upper surface that is fixed in first square plank with the outer space, and interior sky is strained the centre of a circle of straining with the outer space and is coincided with the center of first square plank, at first square plank it strains four highly the same stuffs with the outer space to be fixed with on four angles of upper surface to strain with interior sky, cen