Abstract: Real-time and accurate detection of coal complying with the industrial index is key to the safe and efficient operation of coal-fired power plants. Based on the situation on-site and existing coal quality online analysis technologies ， a coal quality online detection system taking laser-induced breakdown spectroscopy（LIBS） was developed，which realized real-time and swift detection on coal quality. The detection time for a single sample is controlled in 30 min. In the case of successive detection， each sample analysis can be done in 3 minutes. Compared with the traditional manual detection， this system improves the detection efficiency sharply and provides real-time guidelines for thermal power plants. Verified by practical cases ， the contents in coal samples can meet the testing precision required by the coal-fired power plant.The test results can guide the optimized control on the desulphurization and denitration systems of coal-fired boilers， avoid the excessive discharge， reduce the environmental protection cost ， and lower the "carbon tax" by improving the combustion efficiency of boilers.The research is of great significance for improving environmental protection efficiency and economic index of power plants.

Key words: coal quality online detection, laser induce, spectrum, online detection, coal, industrial index