China's thermal power generation accounts for about 80% of the total power generation, while coal accounts for 95% of the thermal power generation. With the rapid growth of the national economy, the problem of air pollution caused by coal burning is becoming more and more serious. According to the current level of emission control, by 2020, the sulfur dioxide, smoke and nitrogen oxides emitted by thermal power plants in China will reach 21 million tons, 5 million tons and more than 10 million tons respectively. If the air pollutants discharged from thermal power plants can not be effectively controlled, it will directly affect the improvement of atmospheric environment quality in China.