Abstract: The operation principle of the slagoff machine was introduced. The defects of the submerged slagoff machine, such as the scraper blade tilted, the guide wheels stopped to rotate due to the wear down of the inner guide wheel, the belt conveyor in the top of the chamber was designed irrationally and others，were analyzed. Some feasible countermeasures were formulated and implemented. The equipment defects occurrence was reduced, and the operation reliability of the slagoff machine system was increased. 

Key words: slag-off machine, scraper blade tilted, inner guide wheel, fault phenomenon