Abstract: In China,TSP,SO2 and NOxwere the main pollutant. Among them,SO2 was the most serious pollutant. Since most of SO2 was from coal combustion,so developing clean coal technology was extremely urgent. The sulfur speciation and existence in coal was introduced. The desulfurization technologies before combustion,sulfur solidifying technologies during combustion and flue gas desulfurization were compared. The mechanism and application of coal desulfurization by microbial pretreatment and flotation separation was introduced.On the surface of pyrite particles,the research of adsorption and modification mechanism of microorganisms was still not deep,there were also no referable industrial application examples. So the introduce of microbiology theory and technology,relevant industrial application promotion were the main measures.