Coal quality on-line detection method and system for direct-fired coal mill of thermal power plant

The invention provides a coal quality on-line detection method and system for a direct-fired coal mill of a thermal power plant, and the system comprises a data collection module which carries out the initial detection of the quality of conveyed coal, and transmits the initial detection information to an information processing module for information storage; the raw material extraction module is used for quantitatively extracting the coal with problems after primary screening; the secondary checking module is used for performing corresponding secondary checking on the coal quality extracted in the raw material extraction module so as to obtain corresponding coal quality data, and transmitting the extracted data to the information processing module; the information processing module is used for correspondingly checking the information acquired by the data acquisition module and the secondary checking module so as to judge the quality of the coal; and the early warning display module is used for receiving the i