This article attempts to analyze the characteristics and hazards of the respirable dust, and introduces the new technologies for respirable dust prevention and control at home and aboard in recent years. Based on analyzing and comparing with different technologies of reducing dust, the results show that charged fog with wetting agent is a high- efficiency technology for the removal of the respirable dust of steel enterprise. Through the theoretical analysis and experimental study, it obtains ideal effect when this dedusting technology is applied to the removal of the respirable dust in a steel enterprise.