The invention discloses an automatic sweeper which comprises a sliding mounting mechanism, a locating mechanism, supporting mechanisms, a height adjusting mechanism and a sweeping mechanism. The locating mechanism and the four supporting mechanisms are mounted on the sliding mounting mechanism, the supporting mechanisms are arranged on the two sides of the locating mechanism respectively, and thelocating mechanism and the supporting mechanisms are in sliding connection with the sliding mounting mechanism. The locating mechanism is provided with the height adjusting mechanism, and the sweepingmechanism capable of carrying out sweeping is mounted on the height adjusting mechanism. According to the automatic sweeper, the sliding mounting mechanism, the locating mechanism, the supporting mechanisms, the height adjusting mechanism and the sweeping mechanism are combined, omnibearing sweeping of an indoor top plate can be achieved, the advantages of being high in sweeping efficiency and low in labor intensity are achieved, and the harm of sweeping dust to people and indoor secondary dust pollution are greatly reduced.