An air supply assembly of an airtight suction device includes: a tubular body, an oxygen supply manifold in communication with the tubular body a scraper fixed in the tubular body and an air supply unit provided in the tubular body and located between the oxygen supply manifold and the scraper. An airtight suction device can further includes a tubular body, an oxygen supply manifold, a first scraper, a second scraper, and an air supply unit.
